What is a kick on a 90?

A kick is a single bend in the tail of a 90° stub that lifts or angles the run before it turns up. You use it to clear something low near the base of the stub, or to bring the foot of the run up to meet a surface, without turning the whole thing into a full offset.

How is a kick different from an offset?

An offset is two bends that step the run over and level it out again. A kick is one bend — the pipe stays angled after it. On a kick 90 the second reference point is the 90 itself, which levels or turns the run at the top, so you only add the one kick bend below it.

Where does the kick mark go?

Down the tail from the 90, at the distance the calculator gives. Bend the 90 first on its own mark, then measure back along the tail to the kick mark and bend the kick. Keep both bends in the same plane so the stub does not twist.

Do I add anything for the kick?

Yes — a kick eats a little length the same way an offset does, and the calculator shows how much. Add it to your overall measurement so the far end of the run still reaches. The 90 take-up is handled separately when the stub mark is placed.

Kick 90 calculator

A kick 90 is a stub-up with one extra bend in the tail to lift the run before it turns up. Enter the finished stub height and your take-up for the 90, then the rise you want from the kick and its angle; the calculator gives the 90 mark and the kick mark, both measured from the end, and the length the kick eats.

Worked example

Say you want a 12 inch stub, your take-up is 5 inches, and a low pipe near the base means you want to kick the run up 3 inches at 22.5°. The 90 mark is 12 − 5 = 7 inches from the end. The kick lifts 3 inches at 22.5°, whose multiplier is 2.613, so the kick sits 3 × 2.613 ≈ 7 13/16 inches past the 90 — about 14 13/16 inches from the end. The kick eats roughly 5/8 inch, which you add to your overall run.

The formula

The 90 mark is the stub mark; the kick is a single bend, so it follows the offset multiplier on its rise:

90 mark = height − take-up · kick from 90 = kick rise ÷ sin θ

A kick is one leg of an offset: the pipe past the bend, of length L, is lifted by L × sin θ, so to gain a kick rise you place the bend rise ÷ sin θ down the tail from the 90. It shrinks the run by the offset shrink of that angle. The 90 keeps its own take-up, which is why the two marks are worked separately and then measured from the same end.

Keep both bends in one plane

Bend the 90 first, on its arrow mark, then roll nothing — bend the kick in the same plane, further down the tail. If the kick twists relative to the 90 the stub leans out of line, and no amount of measuring fixes a bend that is in the wrong plane. Sight down the pipe after the first bend and keep the second true to it.

Questions

What is a kick on a 90?: A kick is a single bend in the tail of a 90° stub that lifts or angles the run before it turns up. You use it to clear something low near the base of the stub, or to bring the foot of the run up to meet a surface, without turning the whole thing into a full offset.
How is a kick different from an offset?: An offset is two bends that step the run over and level it out again. A kick is one bend — the pipe stays angled after it. On a kick 90 the second reference point is the 90 itself, which levels or turns the run at the top, so you only add the one kick bend below it.
Where does the kick mark go?: Down the tail from the 90, at the distance the calculator gives. Bend the 90 first on its own mark, then measure back along the tail to the kick mark and bend the kick. Keep both bends in the same plane so the stub does not twist.
Do I add anything for the kick?: Yes — a kick eats a little length the same way an offset does, and the calculator shows how much. Add it to your overall measurement so the far end of the run still reaches. The 90 take-up is handled separately when the stub mark is placed.

Related tools

90-degree stub-up calculator — the plain stub the kick is added to.
Conduit offset calculator — two kicks that level back out.
Bender take-up — the take-up the 90 uses.