Pipe Offset Calc: Spoolset

A pipefitter's offset calculator. One-time purchase — no subscription, no ads, no accounts.

Enter an offset and a fitting angle and get travel, run and the cut length, with a drawing that redraws as you type — so a mistyped number shows up as a wrong shape before it becomes a wrong cut.

FREE
· Simple offsets at 11¼, 22½, 30, 45, 60 and 90 degrees
· Grade and fall — percent and inches per foot
· Feet-inch-fractions: type 12'6-3/8" the way you write it, or millimetres
· The live drawing, in every mode

UNLOCK ONCE
· Rolling offsets — set and roll in, true offset, travel, and the roll angle to turn the fitting to
· Take-outs — cut length with both fittings subtracted, from ASME B16.9 elbow tables
· Measure your own fitting and save it, for the angles no standard tabulates
· Pipe data — steel schedule 40 and 80, outside diameter, wall, inside diameter

WHERE THE NUMBERS COME FROM
The geometry is verified two ways: published trade multipliers, and a check that rebuilds each offset as 3-D coordinates and measures it without using trigonometry at all — so it cannot share a wrong assumption with the formula it checks. Take-outs are a published table cross-checked against two independent references. Every table names its source inside the app.

BUILT FOR THE JOB
Works with no signal. No account, no sign-in, nothing to lose in a plant room. Glove-sized keys, a fraction key, and a backspace rather than a clear-all. Full VoiceOver support and text that scales to the largest accessibility size.