Rafter Help is the easiest way to calculate rafter length and associated values when building!

Quickly find roof pitch, rafter lengths and ridge height for gable roofs, based on room and ridge width. 
Or calculate length values with more control from the Advanced tab.

Features Include:

- Accurately solve rafter equations
- Enter pitch steepness in radians, decimal degrees or degrees, minutes, seconds (DMS) or rise/run (e.g. 8/12)
- Enter lengths in mm, cm, inches or feet
- Select your preferred number of decimal places

What’s New

Version 1.5

- New Advanced tab for more detailed calculations
- Improved rise/run angle input handling
- Bug fixes

Ratings and Reviews

4.2 out of 5
72 Ratings

72 Ratings

Tryingtobuildit ,

No hip

Save your money there is much better calculators for free on the internet. I assumed it woiuld give me rafter calculations for any type roof I wanted to build, not gonna happen. Specifically hip roof rafters mating 2 different pitches. I also had to figure out format to enter data with onscreen keyboard very annoying. It did function for what it is very limited.

rsshew ,

Worthless garbage

Bought to check personal calculations on a roof design for a shed I was building....waste of time and money. Dimensioning to the center of the ridge beam when the ridge beam size isn’t defined is useless....

Not fort he iPad. ,

Total waste of time and money.

It doesn't solve anything at all.


David Caddy
5.6 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© 2015-2019 David Caddy


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