SettingsSettings for this calculationUS
The total count of 90° elbow fittings in the piping run.
Count every 90° elbow along the run being analyzed for friction loss.
The straight-pipe length that produces the same friction loss as one elbow.
This value depends on pipe size and fitting type — check a fitting equivalent-length table for your specific pipe diameter and material.
The total count of tee fittings where flow branches off the run.
Only count tees where the flow direction changes into the branch; a tee used as a straight run-through typically has a much lower equivalent length.
The straight-pipe length that produces the same friction loss as one branch-flow tee.
Tees typically have a higher equivalent length than elbows of the same pipe size because of the more abrupt flow disruption at the branch.
Total fitting equivalent length
12 ft
They open the calculator with your figures already in it
Pipe Fitting Equivalent Length Calculator: 12 ft — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Total equivalent length = Σ(fitting count × equivalent length per fitting), the standard method for converting pipe fittings into an equivalent length of straight pipe for friction loss calculations
Inputs used
- Number of 90° Elbows
- 4
- Equivalent Length per Elbow
- 1.5 ft
- Number of Tees (Branch Flow)
- 2
- Equivalent Length per Tee
- 3 ft
What this calculation does not cover
- Totals fittings, not the components that usually dominate the head. A coil, heat exchanger, strainer, balancing valve or control valve is published as a pressure drop at a stated flow - feet of head or kPa, not an equivalent length - and on a typical hydronic circuit those together exceed the whole pipe-and-fitting figure. A pump chosen from this total plus the straight pipe alone lands short, and the shortfall turns up as the branch that will not balance.
- One path, not a system. Pump head is set by the INDEX circuit, the single worst route from the pump out to the furthest or most restrictive terminal and back, so the fittings that belong in this box are the ones along that path only. Adding up every elbow in the building inflates the total enormously and buys a pump that overpumps every other branch; the parallel branches get balanced down to the index circuit, they do not add to it.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Total equivalent length = Σ(fitting count × equivalent length per fitting), the standard method for converting pipe fittings into an equivalent length of straight pipe for friction loss calculations
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Tools and safety for this job
To cut and prepare copper pipe, cut and join plastic pipe and solder a copper joint. Generic types, no brands, no prices.
Protection this work requires
- Torch work ignites dust and joists hours later: use a heat mat, keep an extinguisher to hand, and re-check the area an hour after the last flame.
- Knives cause more site injuries than any power tool: cut away from your body, change blades often, and wear cut-resistant gloves to EN 388 level C for repeated cutting.
Cut and prepare copper pipe: Cutting and joining pipe is within reach of a competent DIYer; the system it joins may not be. Work on a gas supply, an unvented cylinder, or a sealed heating system is restricted to a registered installer in most markets, and a tool list is not a qualification.
Cut and join plastic pipe: Push-fit and solvent-weld plumbing is within reach of a competent DIYer. The regulated parts of the system — gas, unvented hot water, and anything notifiable — are not, whatever tools are to hand.
Solder a copper joint: Torch work inside a building starts fires in dust and joists that smoulder for hours after you finish. Where a joint is in an enclosed space or against a timber, a press fitting or a compression joint removes the flame entirely and is usually the better answer.
Show the 6 tools this job needsHide tools
Essential
Blow torch and heat mat
Copper pipe cutter
Deburring tool and wire wool
Plastic pipe shears
Tape measure
Recommended
Adjustable spanner and grips
Also needed as materials: cutting wheels, gas cartridges, solder and flux.
what each plumbing tool is for, and the spec that decides which to buy where one does.