---
title: "Compound 90 Calculator — Two-Bend 90 Around an Obstruction | BendBoss"
description: "Compound 90 calculator: turn a full 90° in two bends (e.g. 45° + 45°) to clear a corner or round obstruction. Get the second angle and the diagonal between bends from the clear depth and first angle."
url: https://bendboss.app/compound-90/
language: en
last_reviewed: 2026-11-14
---

[BendBoss](https://bendboss.app/) › Compound 90

# Compound 90 calculator (two-bend 90)

Sometimes a single 90 would hit something in the corner — a beam flange, a round duct, another run. Splitting the turn into two bends that add up to 90 (30 + 60, 45 + 45, 60 + 30) lets the conduit cut the corner and clear it. The math is the offset multiplier again.

Last reviewed Nov 14, 2026 · Sources at the end of the page

_Interactive calculator on the web page: https://bendboss.app/compound-90/_

The diagonal between the two bends cuts the corner.

## The formula

Second bend = 90° − first bend  
Clear depth = protrusion + clearance (corner) or radius + ½ OD + clearance (round)  
Diagonal between bends = clear depth × multiplier of the first bend

The diagonal works exactly like the distance between bends in an [offset](https://bendboss.app/offset-calculator/): the clear depth is the "offset" and the first bend's multiplier (1 ÷ sin θ, published as 2.0 at 30° and 1.4 at 45° by Greenlee, Klein and Gardner Bender) scales it.

## Worked example: 6″ corner, ½″ clearance, 45° + 45°

  1. Clear depth: 6 + ½ = **6 1/2″**.
  2. Second bend: 90 − 45 = **45°**.
  3. Diagonal: 6½ × 1.414 = **9 3/16″** between the bends.

## Which split to use

  * **45° + 45°** — symmetrical, the most common choice.
  * **30° + 60°** — the first bend leaves the floor gently; good when the obstruction is near the floor end.
  * **60° + 30°** — climbs fast, then eases into the wall.

Keep both bends in one plane, and sight down the run before you strap it. For a large smooth radius instead of two bends, see the [segmented 90](https://bendboss.app/segmented-90/).

## Common questions

### What is a two-bend (compound) 90?

A 90° change of direction made with two bends that add to 90 — for example 45 + 45 — so the conduit cuts the corner and clears something in it.

### How far apart are the two bends?

Clear depth × the multiplier of the first bend. At 45°, a 6½″ clear depth needs about 9 3/16″ between bends.

### How do I clear a round pipe in the corner?

Use the pipe's radius plus half your conduit's outside diameter plus some clearance as the clear depth.

### Do both bends need to be in the same plane?

Yes. If the second bend rolls, the run won't land square on the wall.

## Sources

  * [Greenlee, Aluminum and Iron Site-Rite® Hand Benders Use Guide, 52034125 REV 02 (2023)](https://cdn.greenlee.com/resources/media?key=1adba548-f1d2-43d2-bf44-fe4b89a8b579&languageCode=en&type=document)
  * [Klein Tools, Conduit Bending Basics (Iron & Aluminum Benders)](https://data.kleintools.com/sites/all/product_assets/documents/instructions/klein/ConduitBenderGuide.pdf)
  * [ANSI C80.3 (NEMA), Steel Electrical Metallic Tubing — nominal outside diameters](https://webstore.ansi.org/preview-pages/NEMA/preview_C80.3+HTRJIBA.pdf)

**Every bend on this site, in one app**

BendBoss does offsets, saddles, rolling offsets, stub-ups, kicks, parallel runs (mixed sizes), segmented and compound 90s — fraction keypad, bend diagrams and step-by-step walkthroughs. $25.00 once. No subscription, no ads. English and Spanish.

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## Related bend guides

  * [Segmented 90](https://bendboss.app/segmented-90/)
  * [90° stub-up & take-up](https://bendboss.app/90-degree-stub-up/)
  * [Offset calculator](https://bendboss.app/offset-calculator/)
  * [Offset multiplier & shrink chart](https://bendboss.app/offset-multiplier-chart/)
  * [The BendBoss app](https://bendboss.app/conduit-bending-app/)