Kerfan · Last updated 2026-10-05

Support

Scrolling Is Evil LLC makes Kerfan, a feet-inch-fraction calculator with an editable tape. Write to [email protected]. Tell us your phone model, the app version (in Settings) and what happened. Please do not send client or job details by email.

Pro

The calculator, tape, unit conversions and area and volume results are free. Pro is one purchase through your phone's app store. It adds saved jobs, calculation sheets as PDF or image, and the stair, rafter, diagonal, circle, board foot and concrete solvers. We cannot refund or cancel a store purchase: ask the store you bought from.

Bought on another phone or reinstalled? Tap Restore purchases on the Pro screen or in Settings.

Rounding

The app calculates with exact fractions and rounds only what it shows, to the nearest 1/16 inch unless you change it in Settings. When a shown value is rounded, the app marks it and shows the exact value. Questions about a result are easiest to answer if you send the entries you typed.

Your data

Everything is stored on your phone. If you delete the app or change phones without a phone backup, saved jobs are gone, and we cannot recover them because we never receive them.

Privacy

See the privacy policy.