Fraction Calculator: Feet Inch

The fraction calculator built for the jobsite. Add, subtract, multiply and divide feet, inches and fractions right on a big, glove-friendly keypad — then switch imperial to metric (mm, cm, meters) with one tap. Every answer is exact, right down to the sixteenth (or thirty-second) — no rounding drift, no decimal guesswork. Works completely offline, no signal needed, anywhere on the jobsite. No account, no sign-up.

Stop doing tape-measure math in your head. Joist keeps a running "tape" of everything you calculate, so this morning's number is still there this afternoon — a handy, pocket calculator and unit converter built for construction, woodworking, carpentry, and every trade on site.

FEET-INCH-FRACTION KEYPAD
• Enter feet, inches and fractions (halves, quarters, eighths, sixteenths — any mixed number) with fat, easy-to-hit buttons made for gloves and rough hands
• Add, subtract, multiply and divide measurements — length, width, height, area, and volume, all on the same keypad
• One-tap imperial-to-metric conversion (millimeters, centimeters, meters, yards) for jobs that mix unit systems
• Exact fraction math — no rounding drift, every answer snaps cleanly to 1/16" or 1/32"
• A running history tape you can scroll back through, like a ruler for your math — recall this morning's number again this afternoon without redoing the work

JOBSITE SOLVERS
• Stairs — risers, riser height, treads, total run, stringer length and slope angle, all solved together, with code-limit warnings so an out-of-code rise or run gets flagged before you cut
• Board feet — total board footage and linear lumber for any order, so you know exactly how much to buy
• Rafters — rafter length, run, rise, pitch and cut angle, worked out together for a clean layout (Pro)
• Concrete — slab and tube/column yardage (cubic) with waste allowance, for pours big or small (Pro)
• Drywall — sheets needed for a room, sized to the space (Pro)
• Flooring — boxes needed for any floor, from a small closet to a whole level (Pro)

Every solver ships with a clear, labeled diagram so you can see exactly what each number and material takeoff means — no guessing which measurement goes where.

BUILT FOR CARPENTERS, FRAMERS & BUILDERS
Whether you're a contractor, framer, or weekend DIY handyman — framing a wall, laying out a staircase, ordering lumber, building a deck, pouring concrete, hanging drywall, or estimating flooring — Joist does the fraction and material math so you don't have to. A modern tool for the trades: fast, readable in the sun, and honest about its numbers.

GREAT FOR
• Contractors and framers who need exact feet-inch-fraction math without pulling out a laptop
• Weekend DIY handymen building a deck, laying flooring, or hanging drywall for the first time
• Anyone ordering lumber, pouring concrete, or laying out a staircase and wanting the material math done right

HONEST BY DESIGN
Results are estimates to help you plan and order material. Always verify against your local building code — this app is not a substitute for it.

PRIVATE & OFFLINE
• Works with no signal, anywhere on site
• No account, no sign-up, nothing uploaded
• Your tape stays on your phone, not in the cloud

JOIST PRO (optional)
The free app includes the calculator plus the stairs and board-feet solvers, with ads, and the Site/Daylight themes. A one-time Pro purchase unlocks the rafter, concrete, drywall and flooring solvers, removes all ads, and adds the extra hi-vis Blueprint and Amber themes. Pay once — no subscription.

Whether you're framing a wall, laying out a staircase, ordering lumber, building a deck, pouring concrete, hanging drywall, or estimating flooring, Joist turns tape-measure math into exact feet-inch-fraction answers — on the spot, on any jobsite, with nothing to sign up for.

Download Joist and put an exact fraction calculator in your pocket.