Online Conduit Bending Calculator
By Andrew ·
Quick answer
An online conduit bending calculator does the trig of the trade for you: offsets use 1 ÷ sin(angle) as the multiplier, 90s subtract the bender's deduct, and saddles and kicks are built from the same offset triangle. Enter your measurements above. A 6" offset at 30° gives marks 12" apart, which is a quick way to check any bending calculator.
Calculator
- Results
- Distance between bends
- 8"
- Shrink
- 1 1/16" (1.07")
Worked out the textbook way, from the bend angle alone. BendMate also uses your bender’s radius, deduct and shoe.
What the calculator is doing
Every conduit bend reduces to a right triangle: the height you must move is the short side, the conduit between the two bends is the long slanted side. The calculator solves that triangle for the bend you pick, then adds the corrections for shrink and for your bender.
| Bend | Formula |
|---|---|
| Offset | between bends = height ÷ sin(angle) |
| 3-point saddle | outer marks = height ÷ sin(outer angle), about 2.5 × height |
| 4-point saddle | two offsets, with the obstruction width between |
| Rolling offset | true offset = √(rise² + roll²) |
| 90° stub-up | mark = stub − deduct |
| Parallel offset | shift = spacing × tan(angle ÷ 2) |
Check any answer by hand
A good habit with any calculator, this one included, is to check it once against a number you know.
- Take a 6" offset at 30°. The marks should be 12" apart, because the multiplier is 2.000.
- At 45° the same offset has marks 8 1/2" apart.
- The shrink at 30° should be close to 1/4" per inch, about 1 5/8" for a 6" offset.
- For a 90, the answer should be the stub length less the deduct printed on your bender.
Why different calculators give different answers
A chart or simple calculator treats each bend as a sharp corner. A real shoe bends on a radius and uses a little less conduit, so a calculator that knows your bender will show marks and shrink a fraction smaller than the chart. Neither is wrong; they answer different questions.
- Multiplier calculators give the textbook number, fine for rough layout and for exams.
- Bender-aware calculators include the shoe’s radius and deduct, which matters when a mark has to land within 1/8".
When to use which bend
- Offset to step over by a fixed height and carry on parallel.
- 3-point saddle to hop a pipe, 4-point to cross a beam or duct.
- 90 to turn up a wall; kick to nudge the stub sideways; rolling offset for up and over at once.
- Parallel offsets whenever a bank of conduits has to stay evenly spaced.
On the phone, on site
This page's calculator runs in the browser. BendMate adds 34 benders with their real radius and deduct, 17 bend types, and works offline once it has loaded; it costs $5.99 once.
Get the marks for your bender
BendMate works this out from your bender’s radius and deduct, flags a bend that won’t work, and shows you every mark.
Common questions
Is there an online calculator for bending conduit?
Yes. Enter the height of an offset, the stub of a 90, or the size of an obstruction for a saddle, and the calculator returns the marks and shrink. The ones above run in your browser.
How accurate is a conduit bending calculator?
The geometry is exact. What varies is the bender: its radius and deduct change the real marks by a fraction of an inch from the chart. A bender-aware calculator allows for that.
What formula does a conduit bending calculator use for an offset?
Distance between bends = height ÷ sin(angle), and shrink = height × tan(angle ÷ 2). At 30° that gives a multiplier of 2.000 and 0.268" of shrink per inch.
Can I use the calculator on my phone?
Yes. The page works on a phone browser, so you can read the marks right where you are bending.