Mims Software Co

Strong Sixteenth is a feet-inch-fraction calculator built for framers and carpenters. You type lengths the way you read a tape (5 ft 7 in 3/8), and answers come back rounded to your precision. Each answer says whether the true length is a hair over the mark (strong) or a hair under (shy).

What it does

• Roof: common rafters, hip & valley with the full jack list, irregular hip, collar ties, pitch
• Stairs: risers and treads, stairs with a landing, stairwell openings, ramps
• Layout: layout marks, squaring, equal spacing, rough openings, wall framing, rake walls
• Finish: crown molding, corner miters, polygons, arches, equal courses
• Estimating: concrete, roofing, sheet goods, decking, flooring, block, gravel, paint, board feet, cut optimizer

Built for the jobsite

• Big keys you can hit with gloves on
• An outdoor high-contrast theme for bright sun
• Works in airplane mode, in a basement, anywhere
• Drawings for rafters, stairs and more, so you can check the numbers against the picture

Free and Pro

15 calculators are free for good, with no limits. Some Pro calculators let you try them first. A one-time Pro unlock ($19.99 US) opens every calculator and adds jobs. A job keeps one site's calculations together and builds its cut list, which you can share as text or PDF. There's no subscription and nothing to renew.

Private by design

No sign-up, no ads, no tracking. The app doesn't use the internet, and your numbers stay on your phone. Privacy policy

Strong Sixteenth does the math. You're still the one holding the saw: check your numbers before cutting good stock.