90° Stub-Up Calculator

A stub-up is a single 90° bend that brings conduit to an exact height — out of a concrete slab, into the bottom of a panel, up to a box. The whole trick is one number: take-up.

What take-up is

Every bender head starts the bend a fixed distance before the arrow mark. That distance is the take-up, and it depends on the bender and the conduit size — there is no universal formula, which is why manufacturers stamp it right on the bender head. The rule is simple:

Mark location = target height − take-up

Take-up chart (hand benders, EMT)

Ideal and Klein hand benders agree on these values. Still, always check your own bender's markings — some heads stamp the take-up on the shoe, and shared job-site benders get mixed up.

Worked example

You need a 12" stub with 1/2" EMT: mark at 12 − 5 = 7" from the end of the conduit. Put the arrow on the mark, bend to 90°, and the back of the bend lands at exactly 12".

How to bend a stub-up, step by step

1. Measure from the end and mark at (target height − take-up).
2. Line the bender's arrow up with the mark. Keep steady foot pressure so the conduit does not walk.
3. Bend with smooth strokes to 90°, using the bender's degree marks — not guesswork.
4. Check the result against a square or the floor.

When the height is consistently off

If every stub comes out, say, 1/4" short on your bender, that is not a math problem — it is a calibration problem. Bend one test stub on scrap, measure the error, and apply that correction to every future mark. That single test bend is also how you verify a bender you have never used before.

Mistakes to avoid

• Measuring the mark from the wrong end of the conduit.
• Letting the conduit slip so the arrow drifts off the mark mid-bend.
• Mixing up take-up values between bender brands on a shared job site.