Every calculation a builder needs. One app.
CutOnce replaces the scrap-paper math, the formula Googling, and the "I think that's right" guessing. Here's the full kit.
Rise, run, and everything in between.
Enter total rise and CutOnce calculates code-compliant stairs:
- Number of risers and treads
- Individual rise and run dimensions
- Total run (horizontal distance)
- Stringer length
- Baluster count and spacing for railings
Meets IRC residential stair code defaults. Adjustable for custom specs.
From pitch to cut list.
Enter roof pitch and span. CutOnce returns:
- Common rafter length
- Ridge height
- Birdsmouth cut dimensions
- Overhang / tail length
- HAP and slope in feet-inch-fractions
No trigonometry required.
Hips, valleys, and jacks on the same sheet.
Every hip or valley you run, with the cuts already figured:
- Hip and valley rafter lengths and angles
- Backing angles for every hip
- Cheek cuts for every connection
- King common and jack rafter spacing
Prints alongside the common rafter schedule in the PDF.
Shop-ready PDF plans. Offline.
Every stair, rafter, and hip & valley calculation exports to a PDF ready for the shop or the crew:
- Stair plans with every riser, tread, and stringer call-out
- Rafter plans with lengths, angles, and layout marks
- Print from the truck or share straight to the crew
- Works entirely offline — nothing uploads anywhere
No signal, no cell service, no account required.
Fractions without the headache.
Construction runs on fractions. CutOnce makes fraction math fast, and the feet-inch-fraction calculator stays free forever:
- Add, subtract, multiply, divide fractions and mixed numbers
- Results in simplified fractions. No decimals to convert back
- Handles 16ths, 32nds, and 64ths
- Works with feet-inches-fractions format
Enter 3-5/8" + 2-3/16" and get 5-13/16". Done.
Right angles, squared.
Any right triangle from two known sides. Perfect for squaring walls, checking layouts, and cutting braces:
- Solve the diagonal, rise, or run from any two sides
- Enter in feet-inch-fractions, get results the same way
- Angle output in degrees or pitch
- Ideal for wall squaring and brace cuts
Two sides in. The third side and every angle out.
How much do you need? Exactly this much.
Stop over-ordering. Stop under-ordering. CutOnce calculates material quantities from your dimensions:
- Concrete bags, paint gallons, drywall sheets, deck boards, all from your dimensions
- Waste factors built in so you buy the right amount the first time
- Bag sizes, sheet sizes, board sizes, matched to what's on the shelf
- Deck railing posts and balusters with code-compliant spacing
Know exactly how many bags to buy.
Enter your slab or post hole dimensions and CutOnce tells you how many bags of concrete you need:
- Slab and cylinder (post hole) modes
- 40 lb, 50 lb, 60 lb, or 80 lb bag sizes
- Built-in waste factor, adjustable per job
- Recommends ready-mix when volume hits 1 cubic yard
Volume shown in both cubic feet and cubic yards.
The right number of gallons. Not a guess.
Enter room dimensions and CutOnce calculates how much paint to buy:
- Accounts for multiple coats and coverage rate
- Deducts doors and windows automatically
- Optional ceiling included in the estimate
- Rounds up to whole gallons so you know what to grab off the shelf
Sheets, not square footage.
CutOnce calculates the number of drywall sheets you need, not just area:
- Walls only or walls plus ceiling
- Sheet sizes: 4×8, 4×10, 4×12, 4×14
- Deducts standard doors, windows, and custom openings
- Waste factor included in the final sheet count
Boards, posts, balusters — the whole deck.
Enter your deck dimensions and CutOnce builds the full material list:
- Board count for 2×4, 2×6, 2×8, or 5/4×6 decking
- Perpendicular or diagonal layout with adjusted waste
- Fastener count based on joist spacing
- Railing posts at 6 ft or 8 ft spacing
- Baluster count with 4-inch sphere rule compliance
Square footage and cubic yards. No guessing.
Rectangles, triangles, circles, and irregular shapes. CutOnce calculates area and volume for:
- Rooms and floor plans
- Concrete pads and footings
- Paint coverage
- Mulch, gravel, and fill material
- Storage and container capacity
Feet to meters. Board feet to linear feet. Instantly.
Switch between imperial and metric. Convert area, volume, and length units. CutOnce speaks both languages, and every unit in between.
- Feet / inches / fractions ↔ decimal feet ↔ meters
- Square feet ↔ square meters
- Cubic feet ↔ cubic yards ↔ cubic meters
- Board feet ↔ linear feet (with dimensions)
Try it all free. Unlock it all once.
Download CutOnce free and use every calculator above for 7 days. Keep the feet-inch-fraction calculator free forever. A single $19.99 one-time purchase unlocks all the advanced calculators, plus every future update. No feature gates. No premium tiers. No monthly fees.
See pricing →Built for iPad. Really.
CutOnce isn't a stretched iPhone app. It's a native iPad app with landscape support, side-by-side layout, and a UI designed for the bigger screen.
- Native iPad layout. Not a scaled iPhone UI.
- Full landscape mode support
- See inputs and results side by side
All the math. None of the hassle.
