# Rolling Offset Calculator

URL: https://speedycalculator.com/calculators/construction/rolling-offset/
Last updated: 2026-10-25

> The rolling offset calculator finds the true offset, travel (centre-to-centre pipe length) and run for a pipe that changes both height and side position, for 11¼°, 22½°, 45° and 60° fittings.

## Inputs

- Vertical offset (rise) (in, cm, mm, ft, m)
- Horizontal offset (roll) (in, cm, mm, ft, m)
- Fitting angle

## Results

- True offset
- Travel (centre to centre)
- Travel (fraction)
- Run (setback)
- Travel multiplier

## Formula

```
True offset = √(rise² + roll²)
Travel = true offset ÷ sin(fitting angle)
Run (setback) = true offset ÷ tan(fitting angle)
```

## Explanation

A rolling offset moves a pipe up or down and sideways at the same time. Plumbers and pipe fitters solve it by combining the vertical rise and horizontal roll into a single "true offset" – the hypotenuse of the two – then treating it like a simple offset with the fitting angle. For 45° fittings the travel is 1.414 times the true offset.

### How to use the Rolling Offset Calculator

- **Vertical offset (rise)**
- **Horizontal offset (roll)**
- **Fitting angle**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the vertical rise, the horizontal roll and the fitting angle. The calculator combines rise and roll into the true offset, then uses the angle to find the travel and the run the offset takes up along the pipe line.

### Offset multipliers

FittingTravel = offset ×Run = offset ×11.25°5.1265.02722.5°2.6132.41430°2.0001.73245°1.4141.00060°1.1550.57772°1.0510.325

### Tips for an accurate estimate

- Sketch the job and split irregular areas into rectangles, circles and triangles before you measure.
- Add a waste allowance – typically 5–10% for simple layouts and 15–20% for diagonal, curved or heavily cut work.
- Check the coverage or yield printed on the product, because sizes and densities vary between manufacturers.
- Buy all units of a finished material (tile, brick, siding) from the same batch so colours match, and keep a few spares for repairs.
- Confirm local prices – quarry, lumber and steel prices vary widely by region and season.

### Common mistakes to avoid

- Ordering exactly the calculated amount with no allowance for breakage, offcuts and settlement.
- Forgetting to subtract doors, windows and other openings – or subtracting small ones that still need cutting around.
- Confusing US short tons (2,000 lb) with metric tonnes (1,000 kg) when comparing quotes.

### Inputs explained

FieldWhat to enterVertical offset (rise)Units: in, cm, mm, ft, mHorizontal offset (roll)Units: in, cm, mm, ft, mFitting angleChoose one: 45°, 22½°, 11¼°, 60° …

### What each result means

- **True offset** = sqrt([Vertical offset (rise)]^2 + [Horizontal offset (roll)]^2)
- **Travel (centre to centre)** = [True offset]÷sin(rad([Fitting angle]))
- **Travel (fraction)** = [Travel (centre to centre)]
- **Run (setback)** = [True offset]÷tan(rad([Fitting angle]))
- **Travel multiplier** = 1÷sin(rad([Fitting angle]))

## Worked example

Inputs — Vertical offset (rise): 12 in; Horizontal offset (roll): 8 in; Fitting angle: 45°.

Results — True offset = 14.422 in; **Travel (centre to centre) = 20.396 in**; Travel (fraction) = 20 3/8; Run (setback) = 14.422 in; Travel multiplier = 1.4142.

## FAQ

**What is the 45° offset multiplier?**
1.414 – multiply the true offset by 1.414 to get the travel.

**What are the other multipliers?**
22½°: 2.613, 11¼°: 5.126, 60°: 1.155, 30°: 2.000.

**How do I measure the travel?**
It is centre-to-centre between fittings; subtract fitting take-offs to get the cut length of pipe.

**What formula does the Rolling Offset Calculator use?**
True offset = √(rise² + roll²).