About MeasureTwice

"Measure twice, cut once" is the oldest advice in DIY. MeasureTwice applies the same idea to buying materials: work out what you need before you go to the store.

Every calculator on this site is free, works on your phone, and runs entirely in your browser. Nothing you type is sent to us. Each calculator comes with a plain-English guide covering how to measure, typical depths and thicknesses, and how much extra to allow.

How accurate are the results?

The calculators use standard volume and area formulas, along with typical figures for things like bag yields, paint coverage and stone weight. Real products vary, so treat the results as a solid estimate. Confirm with the product label or your supplier before a large order, and follow local building codes for structural work.

Get in touch

Have an idea for a new calculator or spotted a mistake? Contact us. We read every message.