Measure · Convert · Cut

Roof pitch tools that do the whole job

Measure any roof with the phone already in your hand, convert pitch to degrees in a tap, and print the rafter cut sheet you take up the ladder.

21 free tools  ·  no sign-up  ·  nothing leaves your browser

run 12 rise 6 26.57° rafter
Pitch6/12
Angle26.57°
Slope50%
Multiplier1.118

Every roof pitch tool, in one place

Grouped by what you are actually trying to do, not by alphabet.

Measure a roof in three steps

No ladder, no app, no maths. About ninety seconds start to finish.

Get to a rafter

The attic is the safest place to measure. Any rafter, or the underside of the roof deck, gives the same pitch as the outside surface.

Rest the phone on it

Open the gauge, tap start, and lay the long edge of the phone flat against the timber. The reading settles in about a second.

Tap hold and read

Freeze the number before you move. You get the pitch, the angle, the slope percentage and the multiplier all at once.

The numbers you keep looking up

The common residential band. The full chart runs from a quarter in twelve to twenty-four in twelve.

PitchAngleSlopeMultiplierHip / valley
3/1214.04°25.00%1.0311.436
4/1218.43°33.33%1.0541.453
5/1222.62°41.67%1.0831.474
6/1226.57°50.00%1.1181.500
7/1230.26°58.33%1.1581.530
8/1233.69°66.67%1.2021.564
9/1236.87°75.00%1.2501.601
12/1245.00°100.00%1.4141.732

Built to be checked, not just trusted

Every minimum cites its code

Slope limits come from IRC 2021 Chapter 9 and BS 5534, with the section number next to each figure so you can look it up yourself.

The formulas are on the page

Nothing is hidden in a black box. Each tool shows the arithmetic it used, so you can verify a result by hand.

It works where the signal does not

All the maths runs in your browser. Once a tool page has loaded, it keeps working in an attic with no bars.

Nothing is collected

No accounts, no logins, no measurements sent anywhere. What you type stays on your device.

Common questions

How do I measure my roof pitch?

Hold a level horizontally against a rafter, measure 12 inches along it, then measure straight down to the rafter. That drop is your rise, and the pitch is written as that number over 12. If you have a phone with you, the roof pitch gauge does the same job in one step by reading the phone’s tilt sensor.

What is the most common roof pitch?

Most American homes fall between 4/12 and 9/12, with 6/12 the classic middle ground. UK roofs are quoted in degrees and usually sit between 30 and 45 degrees.

Do I need to get on the roof?

No, and you should not. A reading taken against a rafter in the attic gives exactly the same pitch as the outside surface, and it is far safer. Never go onto a roof without proper fall protection.

Are these calculators free?

Every tool on the site is free, with no sign-up, no account and no limits. Nothing you enter leaves your browser, because all the maths runs on your own device.

Where do the minimum pitch figures come from?

The International Residential Code 2021, Chapter 9, for the US tables, and BS 5534 for the UK ones. Every figure carries its code section so you can check it. Manufacturer instructions and local amendments always take precedence.

Standing in the attic right now?

Open the gauge on your phone, hold it against the nearest rafter, and you will have your pitch before you climb back down.