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.
On the bender
A 90 with a kick behind it: the run comes along the floor, the kick lifts it, and it arrives at the corner already the kick rise up. Bend the corner first, then the kick further down the tail, both in one plane. Because the pipe reaches the corner on a slope, the corner itself is 90° less the kick angle — that is what leaves the stub plumb.
- Measure. The finished stub height, the take-up for the shoe, the rise you want the kick to give the run, and the kick angle you will pull.
- Mark. The 90 mark at height minus take-up from the end. The kick mark further down the tail by kick rise ÷ sin θ (the calculator gives it measured from the same end). Two lines round the pipe.
- Line up. Arrow on the 90 mark, hook toward the end you measured from. Pull the corner to 90° less the kick angle — the kick tilts everything ahead of it, so a full 90 would leave the stub leaning off the wall by the kick angle. A part-bend does not use the whole stamped take-up, so treat the 90 mark as the starting figure and check the finished height on the first one.
- Bend. Slide to the kick mark, arrow on it, pipe still in the same rotation, and pull the kick angle in the direction that lifts the run — no roll between the two bends. Read the angle off the shoe; if the shoe has no line for it, read it with a level.
- Check. Lay the flat run on the floor: the corner should sit the kick rise above it and the stub should stand plumb. A stub that leans sideways means the kick was pulled off-plane; a stub that leans forward or back means the corner and the kick do not add to 90°.
Worked examples
A 12" (305 mm) stub with a 3" (76 mm) kick at 22.5°
Say you want a 12" (305 mm) stub, your bender is stamped 5 (5" (127 mm)), and a low pipe near the base means you want to kick the run up 3" (76 mm) at 22.5°. The 90 mark is 12 − 5 = 7" (178 mm) from the end. The kick lifts 3" (76 mm) at 22.5°, whose multiplier is 2.613, so the kick sits 3 × 2.613 ≈ 7 13/16" (199 mm) past the 90 — about 14 13/16" (377 mm) from the end. The kick eats roughly 5/8" (15 mm), which you add to your overall run.
A 300 mm stub with a 50 mm kick at 30°, metric job
A metric job: the stub finishes at 11 13/16" (300 mm), you have measured your bender's take-up for this pipe at 125 mm, and the run has to kick up 1 15/16" (50 mm) at 30° to clear a slab edge. The 90 mark is 300 − 125 = 6 7/8" (175 mm) from the end. At 30° the multiplier is 2, so the kick goes 50 × 2 = 100 mm past the 90: 10 13/16" (275 mm) from the end. The kick's shrink is 50 × 0.268 = 13.4 → 1/2" (13 mm); add it to the run along the floor.
A 3' 0" (914 mm) stub over a curb, kicked 5" (127 mm) at 30°
A stub has to finish at 3' 0" (914 mm) up a wall, and a concrete curb at the base means the run has to lift 5" (127 mm) before it turns up. Say this bender is stamped 6. The 90 mark is 36 − 6 = 30" (762 mm) from the end. At 30° the multiplier is 2, so the kick goes 5 × 2 = 10" (254 mm) past the 90: 40" (1016 mm) from the end, or 3' 4" (1016 mm) on the tape. The kick's shrink is 5 × 0.268 ≈ 1 5/16" (34 mm), and that comes out of the run along the floor — so if the run was measured at 8' 0" (2.44 m) to the next box, lay it out at 8' 1 5/16" (2.47 m) or the far end lands short.
A short stub and a small kick, exact figures
An 18" (457 mm) stub into a box, bender stamped 5 1/4, with a 2" (51 mm) kick at 45° to get over a cable tray lip. The 90 mark is 18 − 5 1/4 = 12 3/4" (324 mm). At 45° the multiplier is 1.414, so the kick is 2 × 1.414 = 2.83 → 2 13/16" (72 mm) past the 90, which puts the kick mark at 15 9/16" (396 mm) from the end. Shrink on the kick is 2 × 0.414 ≈ 13/16" (21 mm). On a job this small the shop rule (×1.4 → 2.8) lands on the same sixteenth; it is on a 12" (305 mm) kick that the two start to part company.
Try one — a kick 90
Work it on paper, then type the marks. A sixteenth either way counts — that is as close as a tape reads. Two millimetres either way counts.
Loading a bend…
Escriba pulgadas como 12, 1 5/8 o 1' 3 1/2".
What went wrong
A kick 90 is two easy bends, and the mistakes are all about order and direction rather than arithmetic.
The stub leans out of plumb
What you see: the 90 stands up fine, but it tips sideways off the wall by a few degrees.
Why: the kick was pulled a little rotated from the 90. Any twist between the two bends shows up as a lean at the top of the stub, and the taller the stub the worse it looks.
Fix: a pencil line down the length of the pipe before the first bend. Both bends go in with that line straight up. Sight down the pipe after the 90 and again before the kick.
The 90 is the right height but the kick is in the wrong place
What you see: the run lifts too early or too late and misses the thing it was meant to clear.
Why: the kick mark was measured from the 90 bend instead of from the end of the pipe, or from the 90 mark instead of adding to it. The calculator gives both marks from the same end for exactly this reason.
Fix: put both marks on before you bend anything — 90 mark and kick mark, both from the free end. Then bend the 90 first, then the kick.
The run lands short of the box
What you see: the stub is right, the kick is right, and the coupling at the far end is 1" (25 mm) off.
Why: the kick is one leg of an offset and eats length like one. Nobody added its shrink to the run measurement.
Fix: the shrink line in the result. Add it to the overall measurement before cutting or marking the far end — the same habit as on an offset.
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 corner keeps its own take-up, which is why the two marks are worked separately and then measured from the same end — and because the pipe arrives at the corner on the kick's slope, the corner is pulled to 90° less the kick angle for a plumb stub.
Keep both bends in one plane
Bend the corner 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.
Which bender these numbers assume — and how to adjust
The geometry belongs to the angle, not the tool. What the tool changes — its reference marks, its take-up and gain, its springback — is yours to read off the shoe or prove on scrap, never a table here (the four test bends). For this bend:
The 90 mark goes on the arrow with the typed take-up; the kick mark goes on the arrow too, and its angle is read off the degree scale — a kick is one bend of an offset. The catch is the degree scale: look at what your own shoe is actually marked for, because a kick at an angle between its lines is a guess unless you read it with a level. Pull the kick, check the real angle, and if it is not what you asked for, put the real one in "Other angle" and re-read the kick mark before the next stick.
Preguntas
- 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.