How we check

Two publishers per fact

Every fact on HowMuchIt rests on at least two independent publishers: makers' own product pages, government agencies, university extension services and trade associations. Two pages of one publisher count once. A clause that only one publisher supports is cut, not softened.

Your price, not ours

Our calculators work out how much of something you need. When you type your own price, the calculator multiplies it for you, in your browser. We never write a price: prices change from store to store and week to week, and you know yours.

Numbered sources

Each fact carries small numbers that point to its sources at the bottom of the page, with a link to the exact page we read. When sources give different numbers, we write the range both support, or we leave the number out.

Affiliate links

Some pages end with a box of eBay search links, and the header has an eBay search box. As an eBay Partner Network affiliate, we earn from qualifying purchases. Both are labeled as ads, the links never change what a page says, and the facts on our pages never come from a seller.

What we never do

• We never write a price.
• We never invent a quote, a review or a source.
• We do not replace a licensed electrician, plumber or engineer: for wiring, gas, structure or permits, ask one.

How these pages are written

The pages are written with an AI assistant, then every fact is checked against its sources before it is published. If you find an error, write to us and we will fix it.