The rise is the whole allowance
Every ramp problem starts as one vertical measurement and turns into an argument about horizontal distance. Shoot the finish floor at the door, shoot the finish grade where the ramp will meet the walk, and the difference between them is the whole allowance you have to spend. Nothing downstream changes that number - not the handrail detail, not the mix design, not how the owner feels about switchbacks. Read the rise wrong by an inch and you find out at the top landing, in cured concrete, on the morning the inspector shows up.
Shoot to finished surfaces, not to whatever is under your feet today. A threshold scheduled for replacement, a walkway due for a two-inch asphalt overlay, a stoop that has settled since the building went up - each moves the rise after the run has already been committed on a site plan. On renovation work, take the reading at three points across the door opening. Existing slabs are rarely level, and the corner with the most rise is the corner your allowance has to cover.
Thresholds deserve a separate reading. Changes in level at a doorway are treated on their own terms in the accessibility standards, and a raised sill can eat a fraction of the allowance before the ramp begins - or hand you back an inch if it can be reset during the same job. Where the door swings out over the top landing, the swing takes plan area as well, a different account that overdraws just as fast.
What an inch of rise buys
The published maximum for a ramp on an accessible route in the United States is 1:12 - one unit of rise for every twelve of run - under the ADA Standards for Accessible Design, carried through ICC A117.1 and the accessibility chapter of the International Building Code. At that exchange rate an inch of rise costs a foot of run. Residential work permitted under the International Residential Code follows a different path and allows a steeper ramp where a shallower one is technically infeasible; which document governs your job is a question for the building official, not for the drafter.
Designing to the maximum is how a ramp fails inspection while being built exactly as drawn. Forms move, screed rails deflect, a finisher chases a low spot, and the surface ends up a fraction steeper than the line on paper. Draw at 1:16 or 1:20 wherever the site allows and ordinary field variation still lands inside the limit. Draw at 1:12 and every variation becomes a violation. The standards acknowledge conventional industry tolerances, but no inspector has a published number to grant you, so the only margin you can rely on is the one you built in yourself.
A second charge lands on the account before you have spent a foot: a ramp run may rise no more than thirty inches before a landing interrupts it. Forty inches of rise is therefore never a single ramp. It is two runs and at least three landings, and landings are not free. Sketching a total rise as one continuous sloped line is the most reliable way to hand an owner a footprint that comes out fifteen feet short once it is drawn properly.
Rise, design slope, the thirty-inch run ceiling and the landings it forces all pull against the same total, so settle the geometry here before a footprint gets committed to a site plan.
The total vertical height the ramp must climb.
Total ramp horizontal length
53 ft
This restates the fixed ADA 2010 Standards ramp geometry requirements (1:12 max slope, 30 in / 762 mm max rise per run, 60 in / 1,524 mm min landing length) for total horizontal length planning — it does not check ramp width, cross slope (max 1:48), edge protection, surface requirements, or handrail specifications (see the companion handrail extension calculator), all of which are separately required for full compliance.
- Number of ramp runs
- 2 runs
- Intermediate landings required
- 1 landing
They open the calculator with your figures already in it
Commercial ADA Accessible Ramp Length & Landing Calculator: 53 ft — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
What this calculation does not cover
- The landings at the two ENDS are not in this number. A ramp needs a level landing at its top and at its bottom, each at least 60 inches (1,524 mm) in the direction of travel, and neither is in the total returned here — so a ramp that fits the measured space on this figure will overrun it by roughly 10 feet (3 m) once both ends exist. Intermediate landings are counted; the terminal ones are not.
- 1:12 is the code ceiling, not a design target, and this page is hardcoded to it. Built at exactly 1:12 a ramp has no construction tolerance at all — a slab poured a fraction of an inch steep anywhere along the run measures non-compliant — and it is also the hardest legal slope for someone to self-propel up. Designing shallower means multiplying the rise by 16 or 20 yourself, because this total will always be the shortest ramp the standard permits, never the most usable one.
- A landing that turns is a bigger landing. This adds 60 inches of straight travel per intermediate landing, which is right only where the ramp carries on in the same direction. Switch back — which is how a long ramp fits a real site — and that landing must be at least 60 by 60 inches with the ramp width setting the other side, at which point the answer stops being a length and becomes a footprint to lay out on plan. The same goes for any landing a door opens onto, where the door's maneuvering clearance is required on top of the 60 inches.
Code thresholds this tool can check
Code thresholds this tool can check
Checked for United States. Each check below names the body that published the limit it uses. Switching market re-runs them. This is not a code review and has no official standing.
These checks cover only the specific numeric limits listed below. They are not a complete code review: fire separation, egress, structural capacity and accessibility provisions are outside their scope, and only the handful of local amendments offered in the selector are modelled — your municipality may have others. Passing every check here does not make a design compliant. Final approval rests with your local building authority.
WITHIN LIMIT — Maximum running slope 1:12; maximum rise 30 in (762 mm) per run.
Rise of 48 in exceeds 30 in, so 1 intermediate landing(s) are mandatory — they are included in the length above.
US Access Board · 2010 ADA Standards §405.2 / §405.6 · 2010 ADA Standards §405.6
Landings are a fixed charge
Landings come out of the allowance as a fixed charge rather than a rate. Every ramp needs one at the top and one at the bottom, each at least sixty inches long, at least as wide as the run it serves, and level in both directions within the same cross slope limit that governs the ramp surface. That last requirement catches people out: a landing is not a place to shed the water you did not want on the ramp.
Turns cost more than straight landings. A change in direction requires a landing at least sixty inches by sixty inches, and a switchback consumes that square plus the width of both runs plus the clearance the handrails need between them. Lay a switchback out on the survey before quoting it. The footprint is regularly twice what an owner has pictured, and the second run frequently ends up over a planting bed, a downspout discharge or the drive aisle striping.
Doors complicate the top landing more than any other element. Maneuvering clearance is required on the landing side, and the dimension changes with the approach direction and with whether the user is on the push or pull side - the tables in the standards govern, and they are not interchangeable between a forward approach and a latch-side one. A landing sized only to the sixty-inch minimum often fails because the door needs more room than the ramp does.
Before a switchback is drawn, check the square you are proposing to turn in against the clear circle a chair actually needs - the two are easy to confuse on a site plan at 1:200.
The available clear width of the floor space.
The available clear depth of the floor space.
Limiting available dimension
5 ft
MEETS the 60 in (1,524 mm) circular turning space minimum. This checks only the 60-inch (1.524m) circular turning space requirement of ADA Section 304.3.1 — it does not check the alternative T-shaped turning space option (Section 304.3.2), floor slope (max 1:48), surface requirements, or obstructions/protrusions into the space.
- Required minimum diameter (ADA 304.3.1)
- 5 ft
They open the calculator with your figures already in it
Wheelchair Turning Space Clearance Checker: 5 ft — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
What this calculation does not cover
- Two dimensions can only describe a rectangle. A bathroom that wraps around a vanity, or a landing that narrows past a radiator, has no single clear width and depth — enter the overall room and this reports a pass while no 60 in circle actually fits anywhere in the clear area. What has to fit is one continuous unobstructed circle in one location, and on an irregular plan that gets drawn, not measured twice.
- The turning circle is one geometry in the room and it has to coexist with others. Maneuvering clearance on the pull side of the door and clear floor space at each fixture are separately dimensioned areas with their own rules, and a room can hold a compliant circle while the door approach or a fixture approach has nowhere to go. They are permitted to overlap one another, which is what makes this a layout exercise rather than a sum of areas.
- 60 inches is this document's minimum, not a design target and not the only figure in play. Larger powered chairs and mobility scooters need more room to come about than the minimum circle allows, and a space held to a different standard — a dwelling unit, or a jurisdiction working from ICC A117.1 rather than the 2010 ADA Standards — is measured against that document's own dimensions instead of this one.
Cross slope and drainage draw on the same account
Cross slope draws on a separate account with a much smaller balance: 1:48, roughly a quarter inch per foot, measured perpendicular to the direction of travel. That figure is a ceiling not to exceed rather than a target to hit, and it applies to landings as well as runs. A wheelchair on a surface tipped past the limit veers, and the user corrects with one arm the whole way up.
Water still has to leave the surface, and the same quarter inch per foot that drains a slab is the entire cross slope allowance. No room exists to crown a ramp. Pitch it one way, to one side, and confirm the receiving grade on that side actually takes the water instead of ponding against the curb. Landings are the harder case, since they must stay effectively level in every direction while still draining; on exterior work the surrounding grade usually does that job.
Texture and openings sit alongside slope among the things most easily lost during finishing. Exterior ramp surfaces must be slip resistant, which in cast concrete means a broom finish drawn perpendicular to the direction of travel, not diagonally to match the adjacent walk. Openings in the walking surface must not pass a half-inch sphere, and where a grating falls in the path the elongated openings run perpendicular to travel so a caster cannot drop in.
Cross slope arrives on site as a fall in millimetres across a width in metres, and it has to be converted before anyone can say whether that fall clears 1:48 or quietly breaks it.
The vertical change in height over the run.
The horizontal distance over which the rise occurs.
Slope grade
8.974 %
- Angle
- 5.13 degrees
They open the calculator with your figures already in it
Slope & Grade Calculator: 8.97 % — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
What this calculation does not cover
- Run is taken as the true horizontal distance between the two ends, and nothing converts a tape laid along the sloping face into that horizontal — measure along the surface instead and the grade reads lower than the ground really is, with the gap widening as the slope steepens.
- Rise is read as a magnitude only, so a drop and a climb of the same size return the same positive grade and a negative entry is floored to zero; which end is higher stays your own note rather than something the answer carries.
- Both figures describe a single straight line drawn between the two points you measured, so any crest, dip or bench sitting between them is averaged away, and cross-fall across the width of a drive or path is not part of the arithmetic at all.
- The output covers grade percent and the matching angle; the sloping distance itself — what you would order ramp board, handrail or edging against, and always longer than the run — is not worked out, nor is the result expressed as the 1-in-X ratio that specifications are often written in.
- No ceiling is applied to the outcome: a 2% fall and a 45% bank come back with identical confidence, and the accessible-ramp and driveway grade figures quoted in the questions below are context for reading your number, not a test the calculation runs against it.
Handrails spend the budget past the ends of the ramp
Handrails become mandatory on both sides of a run once the rise exceeds six inches, with the gripping surface between thirty-four and thirty-eight inches above the ramp surface and continuous along the full length of each run. Gripping surfaces carry prescribed cross-section limits - a circular rail within a defined diameter range, a non-circular one within a defined perimeter - plus a required clearance between rail and adjacent wall. Rails that are structurally sound but the wrong diameter still get rejected, and replacing them afterward means new posts, new core holes and new patching.
Twelve inches of horizontal extension beyond the top and bottom of each run is the part of the handrail that spends site budget rather than ramp budget. Those extensions run level, parallel to the floor, and they land somewhere - on a landing, across a walk, past a door swing. They must not reduce the clear width required for whatever route they encroach on, and they cannot be trimmed because a door leaf hits them; the door or the landing moves instead. Ends get returned to a wall, a post or the ground so a sleeve or a bag strap cannot catch.
Switchbacks change the handrail geometry again. The inner rail on a switchback or dogleg runs continuously between the two runs rather than stopping and restarting at the landing, so the fabricator needs final landing geometry before bending anything. Edge protection belongs in the same pass: a curb, barrier or extended surface along each side of every run and landing, sized so a four-inch sphere cannot pass beneath near the walking surface. Providing it on the runs and stopping it at the landings is a routine punch item.
The extension past each run end is charged to the landing or walk it lands on rather than to the ramp, so work out that encroachment before posts are set and rail is bent.
The sloped (along-the-ramp) length of this single ramp run.
Total handrail length needed
21.5 ft
This restates the fixed ADA Section 505.10.3 handrail extension requirement (12 inches / 305 mm minimum at each end) only — it does not check handrail height, gripping surface dimensions, or structural mounting requirements, which are separately specified.
They open the calculator with your figures already in it
ADA Ramp Handrail Extension Calculator: 21.5 ft — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
What this calculation does not cover
- This is ONE rail. A ramp run rising more than 6 inches (152 mm) needs handrails on both sides, so the linear material to buy is twice this number, plus the posts or brackets carrying the second run. It is the single commonest way a handrail order arrives at half the length the ramp needs.
- Multi-run ramps do not simply add up run by run. Where the rail is carried continuously across an intermediate landing into the next run, it is continuous — you do not get two 12-inch extensions there, you get the landing's full length of rail, 60 inches (1,524 mm) minimum — and the extension requirement then applies only at the true top and bottom of the whole ramp. Adding this per-run figure blindly undercounts a continuous rail and overcounts a broken one.
- The extension runs horizontally above the landing and has to terminate somewhere: returned to a wall, to a guard, or down to the landing surface, or continued into the adjacent run's handrail. That return, plus the bend from slope to level at each end, is rail and fittings this straight addition of 12 inches (305 mm) does not include — and a rail cut to exactly this length ends in a free end, which is the end that catches a sleeve or a shoulder strap.
When the budget will not close
Sometimes the arithmetic will not close, and the honest move is to say so before anyone forms a footing. Lengthening the run is the first lever and switching back the second, but both assume site to spend. Where there is none, the productive question is whether the rise itself can be reduced: resetting a threshold, lowering the walk at the bottom, regrading the approach over a longer distance, or moving the accessible entrance to a face of the building where the grade already sits close.
Regrading gets dismissed too early on most jobs. Dropping the finish grade three inches at the bottom buys three feet of run at 1:12 and more at a gentler slope, and it often means resetting only a short stretch of walk that was going to be replaced anyway. Check what the drop does to surrounding drainage, to any catch basin rim, to tree roots, and to the continuous accessible route back toward parking or the public sidewalk, where right-of-way guidance rather than the building standards may govern.
Platform lifts are a last option rather than an equivalent one. Permitted only in limited circumstances under the accessibility standards, they carry an ongoing maintenance and inspection obligation and leave the owner with a device that can be out of service on the day it matters. A ramp that fits, even an ugly one switching back twice across a lawn, is a better handover than a lift that fits only the drawing.
Building to the budget you drew
Settlement converts a compliant 1:16 into a non-compliant 1:11 without anyone touching the ramp, which makes the footings an accessibility detail and not merely a structural one. Bear below the local frost depth, isolate the structure from the building so differential movement does not tip the top landing, and compact fill under a slab-on-grade run in lifts rather than one dump. Retrofit ramps poured on unprepared fill against an existing foundation are the ones that come back.
Set screed rails to elevations, never to a percentage. Establish top and bottom finish elevations from the same benchmark used for the original rise reading, string or laser between them, and mark intermediate stakes every eight to ten feet so a sagging rail shows before the pour rather than after. Calibrate the digital level on a surface you have verified flat, then check it again after it has ridden in a truck bed for a week; an instrument reading two tenths of a degree light will pass a ramp that the inspector's instrument fails.
Pour sequencing decides how the transitions come out, and transitions accumulate most of the slope error. Place runs, landings and any integral curb together where the pour size allows, so the joint between them is not also a change in plane. Put an isolation joint at the building, control joints at spacing suited to the slab thickness and mix, and keep every joint square to the path of travel. Vertical lipping at a joint is limited to a quarter inch, and anything between a quarter and a half inch has to be beveled.
Panel length sets where the joints fall, and on a ramp those positions are also where lipping will later be measured, so they are worth placing on paper rather than by eye behind the screed.
The total length of the sidewalk run.
The maximum unbroken panel length allowed between control joints.
Control joints needed
19 control joints
They open the calculator with your figures already in it
Concrete Sidewalk Control Joint Spacing Calculator: 19 control joints — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
What this calculation does not cover
- Counts joints and says nothing about how they are made, which is what decides whether they work. A control joint has to be cut or tooled to at least a quarter of the slab depth — 25 mm (1 in) in a 100 mm (4 in) walk — and it has to be there early, tooled while the concrete is plastic or saw-cut within hours of set, before shrinkage stress finds its own path. A perfectly spaced joint that is too shallow or cut too late does not crack the slab on your line; the slab cracks where it wants and the joint sits empty.
- The sidewalk's WIDTH never enters this sum. Panels want to stay near square — beyond about one and a half times the width they crack across the middle whatever the joint count says — so a maximum panel length typed in without checking it against the actual width produces long thin panels that crack anyway. On a 1.5 m (5 ft) walk the real ceiling is around 2.2 m (7 ft), not whatever this box will accept.
- Control joints are not the only joints in a sidewalk. Full-depth isolation joints with a compressible filler go where the walk meets a building, a step, a driveway, a hydrant or a light pole, so the slab can move without dragging on them — a different detail, a different material and a quantity this count does not produce. Tool a control joint where an isolation joint belonged and the walk cracks off the fixed object instead.
Where the inspection finds the overspend
Inspectors measure with a short digital level, commonly twenty-four inches, walked along the run and across it, and the worst reading governs rather than the average. That single fact reframes the whole job: an average of 1:14 is worth nothing if a two-foot stretch reads 1:11. Measure it yourself the same way before calling for inspection - at the top transition, at the bottom transition, at mid-run, and diagonally across each landing.
Four failures recur often enough to check by name. The bottom two feet, where a crew feathered the new ramp into an existing walk and picked up the walk's slope. The cross slope at the top landing, tipped to move water away from a door. The handrail extension cut short to clear a door leaf or a column. And edge protection run along the ramp but stopped at the landing, which is exactly where a caster goes off.
Fixing a finished ramp costs far more than the error suggests. Grinding corrects a small high spot and destroys the broom finish doing it; slab jacking moves a panel but rarely lands it inside a quarter inch per foot; most real corrections mean saw cutting, removing and repouring a section, then rebuilding the handrail anchored to it. Beyond that, ADA obligations run as civil rights law rather than as a building code ticket, so a ramp signed off and later measured out of compliance stays the owner's exposure long after the permit closes.
Slope budget takeoff
Six numbers decide whether the ramp closes on the site you actually have. Fix them before ordering steel or forming anything.
- Total rise, read at finished surfaces — Three readings across the door opening; account for any planned overlay or threshold change.
- Run length at design slope, not maximum slope — Draw 1:16 or 1:20 where site allows so field variation stays inside the 1:12 ceiling.
- Landing schedule: one per thirty inches of rise, plus top and bottom — Sixty inches minimum length, sixty by sixty at every change of direction.
- Handrail extensions, twelve inches horizontal past each run end — Confirm they clear door swings and do not narrow the walk they land on.
- Edge protection continuous along runs and landings — Curb, barrier or extended surface; the landing is the piece most often skipped.
- Cross slope verified at 1:48 or flatter — Twenty-four-inch digital level, calibrated, worst reading governs - check transitions first.
Opens the calculators above on one screen with the dimensions from this article already filled in. Quantities only — this site publishes no price list, because local prices vary too much to publish honestly.