Flexible Pavement AASHTO Structural Number (SN) Calculator
Calculate a flexible pavement's structural number (SN) from its layer thicknesses and layer coefficients, per the AASHTO 1993 design method.
Imperial / Metric
Materials & Quantities
Paving, hardscape & site structures
Road, yard and footway surfaces, and the things set into and beside them.
- 31Calculators
- 30Work in imperial
- 31Work in metric
What this covers
Asphalt tonnage, prime and tack coats and in-place density against Gmm; pavement design by AASHTO structural number and the edge stress an airfield slab sees; crown and cross-fall; pavers with their base, edging, jointing sand and pedestals; and the concrete elements of a paved surface — kerb and gutter, joint spacing, dowel bars, barriers, bollards.
What decides which one you need
Flexible or rigid. A flexible pavement is a layer-thickness problem answered in tonnes and structural number; a rigid one is a slab problem answered in volume, joint spacing and load transfer. They share a subgrade and almost nothing else, and a page written for one is not a conservative version of the other.
What this does not cover
The base and sub-base under the surfacing, which is earthworks, and the drainage carrying water off it.
Every calculator in this family
31 calculators
Rigid Airfield Pavement Edge Stress Screening Calculator
Calculate the Westergaard edge stress in a concrete airfield pavement slab under a single wheel load, as a preliminary screening check.
Metric
Asphalt In-Place Density (Percent of Gmm) Calculator
Turn a pavement core's two specific gravities into percent of Gmm and the air void content that goes with it.
Asphalt Emulsion Prime Coat Calculator
Calculate the asphalt emulsion prime coat material needed for a granular base course before paving.
Imperial / Metric
Asphalt Tack Coat Calculator
Calculate the asphalt tack coat material needed between paving lifts.
Imperial / Metric
Roadway Base Course Aggregate Tonnage Calculator
Calculate the tonnage of aggregate base course material needed for a roadway.
Imperial / Metric
Security Bollard Spacing Calculator
Calculate the number of bollards needed to protect a length of frontage at a maximum spacing.
Imperial / Metric
Chain Link Fence Post Spacing Calculator
Calculate the number of line posts needed for a chain link fence run.
Imperial / Metric
Concrete Curb and Gutter Volume Calculator
Calculate the concrete volume needed for a combined curb-and-gutter roadway section.
Imperial / Metric
Gravel Base Layer Tonnage Calculator
Estimate the tonnage of crushed stone or gravel base needed for a pavement or slab sub-base layer.
Imperial / Metric
Highway Guardrail Post Spacing Calculator
Post count for a W-beam highway guardrail run, at the AASHTO tangent spacing or the tighter spacing a transition calls for.
Imperial / Metric
Concrete Barrier (Jersey Barrier) Segment Count Calculator
Calculate how many standard-length precast concrete barrier segments are needed for a run.
Imperial / Metric
Landscape Fabric Calculator
Estimate how many rolls of weed barrier landscape fabric you need for a garden bed or path.
Imperial / Metric
Lawn Edging Calculator
Coils or straight lengths of lawn and bed edging for a measured edge, straight or curved, open or a closed bed, with the joints and the stakes along it.
Imperial / Metric
Manhole Ring/Riser Segment Calculator
Calculate how many standard riser rings are needed to build a manhole to its required depth.
Imperial / Metric
Open-Graded Bedding Course Stone Calculator
Loose volume and delivered tonnage of the screeded No. 8 bedding course under permeable pavers, with the allowance for it closing up under compaction.
Imperial / Metric
Parking Lot Stall Layout Calculator
Calculate how many parking stalls fit along a single row of usable parking lot length.
Imperial / Metric
Concrete Pavement Dowel Bar Calculator
Size and count load-transfer dowel bars for a concrete pavement joint, using standard ACPA sizing guidance.
Imperial / Metric
Paver Base & Sand Calculator
Estimate the gravel base and bedding sand volume needed under a paver patio or walkway.
Imperial / Metric
Paver Calculator
Estimate how many pavers you need for a patio or walkway, based on paver size and area.
Imperial / Metric
Paver Edging Calculator
Estimate how many sections of paver edging (restraint) you need around a patio or walkway's perimeter.
Imperial / Metric
Paver Polymeric Sand Calculator
Estimate how many bags of polymeric sand you need to fill the joints in a paver patio or walkway.
Imperial / Metric
Permeable Pavement Joint Fill Stone Calculator
Jointing stone for a permeable pavement: the first fill, the top-up the joints take during compaction, and what each later replenishment round needs.
Imperial / Metric
Raised Garden Bed Soil Calculator
Estimate how many bags of soil you need to fill a raised garden bed.
Imperial / Metric
Roadway Striping Retroreflective Drop-On Bead Calculator
Calculate the glass bead material needed for retroreflective drop-on application over roadway striping paint.
Imperial / Metric
Roadway Crown Cross-Slope Calculator
Calculate the elevation drop from a roadway's centerline crown to its edge, for a target drainage cross-slope.
Imperial / Metric
Built-In Bench/Planter Seat Wall Concrete Volume Calculator
Calculate the concrete volume needed for a built-in landscape bench or planter seat wall.
Imperial / Metric
Concrete Sidewalk Control Joint Spacing Calculator
Calculate the number of control joints needed along a concrete sidewalk run.
Imperial / Metric
Traffic Sign Post Foundation Concrete Calculator
Calculate the concrete volume needed for a cylindrical traffic sign post foundation.
Imperial / Metric
Speed Bump/Hump Material Volume Calculator
Calculate the asphalt or rubber material volume needed for a speed bump, accounting for its rounded cross-section.
Imperial / Metric
Decorative Water Feature Pump Flow & Turnover Calculator
Calculate the pump flow rate needed to turn over a decorative fountain or water feature basin within a target time.
Imperial / Metric