All Measurements

Select a measurement below to see exactly how long it is with an actual-size ruler and real-world comparisons.

1" inch 2.54 cm 2" inches 5.08 cm 3" inches 7.62 cm 4" inches 10.16 cm 5" inches 12.7 cm 6" inches 15.24 cm 7" inches 17.78 cm 8" inches 20.32 cm 9" inches 22.86 cm 10" inches 25.4 cm 11" inches 27.94 cm 12" inches 30.48 cm 13" inches 33.02 cm 14" inches 35.56 cm 15" inches 38.1 cm 16" inches 40.64 cm 17" inches 43.18 cm 18" inches 45.72 cm 19" inches 48.26 cm 20" inches 50.8 cm 21" inches 53.34 cm

Every length from 1 to 21 inches

Twenty-one dedicated pages, one for each whole inch. Each page draws that exact length as a real ruler on your screen and pairs it with ten objects you already know — a credit card for short spans, sheet of paper in the middle, door widths near the top. Pick any number above to see its true size, or start with the everyday favorites: a 6-inch hand span, the 12-inch foot, or a 21-inch monitor width.

Chetan Kumar, creator of How Long Is an Inch?

Hi, I'm Chetan Kumar — an SEO specialist from India, and I own and maintain this site. I built it after ordering a 7-inch burrito and realising I had no idea how long 7 inches actually was. Everything runs in your browser — no app, no install, no sign-up — and every measurement method is documented. Spotted a mistake? Email me and I'll fix it. More: About | How We Measure | Email | GitHub

Last updated: November 2026