About DIY Home Calcs

DIY Home Calcs is a free collection of calculators and guides that help homeowners, renters and DIYers work out how much material a project needs before they buy it.

Why we built it

Most material mistakes happen in the aisle of a hardware store, with a phone in one hand and a rough measurement in the other. We wanted calculators that load instantly on a phone, ask only for the measurements you actually have, and round the answer to what the store sells: bags, boxes, rolls, sheets and gallons.

How the calculators work

Every calculator uses standard geometry (area and volume) combined with typical product figures such as paint coverage per gallon, the yield of a bag of concrete, or the weight of a cubic yard of gravel. Each page shows the exact formula, a worked example you can check by hand, and the assumptions behind it, so you can adjust the inputs for your specific product.

The calculations run entirely in your browser. We don't ask you to sign up, and the numbers you type are not sent to us.

Accuracy and corrections

We check each formula against worked examples and automated tests. Product values like coverage and yields vary by brand, so we always recommend reading the label and confirming large orders with your supplier. If you spot an error or want a calculator we don't have yet, please contact us; we read every message and correct mistakes promptly.

How the site is funded

DIY Home Calcs is free to use and is supported by advertising. Ads never change the results of a calculator. See our privacy policy for details on how advertising cookies are used.