Clirto Construction Calculator: Feet, Inches & Fractions

Add, subtract, multiply and divide feet, inches and fractions in a side panel. Exact answers with the steps shown.

Clirto Construction Calculator works in the units you actually read off a tape: feet, inches and fractions of an inch. It opens in Chrome's side panel, so it stays beside your plans, supplier quotes or emails while you work. Type lengths the way you say them: 5' 3 1/2" + 2' 4 3/4" = 7' 8 1/4". Every answer comes with the working, so you can see how it was reached, and a check that runs it backwards. WHAT IT DOES • Add, subtract, multiply and divide lengths in feet, inches and fractions. • Multiply two lengths to get an area (10' 6" × 8' = 84 sq ft) and three to get a volume. • Divide a length into equal parts, or divide one length by another. • Exact fractions inside: answers are worked out exactly and rounded only when shown, to the nearest 1/2, 1/4, 1/8, 1/16, 1/32 or 1/64 inch. When the exact answer is not on a mark, it tells you which mark it was rounded to and how far off that is. • Fraction keys for 1/2, 1/4, 1/8, 1/16 and 1/32, plus a / key for any other fraction. • Accepts yards, metres, centimetres and millimetres as well (1 inch is exactly 25.4 mm). • Shows the answer as feet and inches, decimal feet, decimal inches or millimetres. • "Read as" line when your input was understood differently from how you typed it, for example the architect's 5'-3" notation. • History of your last answers, and a Copy button. • Works from the keyboard: digits, ' and ", + - * /, Enter, Backspace, Escape. Paste a measurement straight in. • Light and dark themes, following your browser. • Keyboard shortcut Alt+Shift+K opens the panel (you can change it at chrome://extensions/shortcuts). PRIVATE AND OFFLINE The calculator runs entirely on your device. It needs no account, makes no network requests, and the only permission it asks for is "sidePanel", to show itself in the side panel. It cannot read the pages you visit. Your history and settings are saved in the extension's local storage on your computer and nowhere else. WHAT IT DOES NOT DO It does not do stairs, rafters or roof pitch, and it has no fractions finer than 1/64 inch. On clirto.com there are separate free calculators for square footage, board feet, concrete, stairs and more, each with the working shown. Clirto is an independent website. This extension is not affiliated with, or endorsed by, any calculator maker. Requires Chrome 116 or newer.