MaterialMath is a small, independent collection of free calculators for homeowners, DIYers and tradespeople who need to turn measurements into an order list.
We built it because most material estimates go wrong in the same few places: unit conversions (inches of depth against feet of length), forgetting waste, and not knowing how a product is actually sold. Each calculator handles those steps for you and shows its work.
How we build our calculators
- Published formulas. Every page explains the formula it uses and includes a worked example you can reproduce by hand.
- Stated assumptions. Bag yields, coverage rates, densities and default waste factors are listed on each page and taken from common manufacturer specifications and trade references. Where products vary, we let you change the assumption.
- Tested. Each calculator is covered by automated tests that check its results against hand-calculated examples.
- Private by design. Calculations run entirely in your browser. Your numbers are never sent to us.
Corrections
If you spot an error or have a suggestion, please get in touch. We review and fix reported issues promptly and update the "last reviewed" date on the page.
Disclaimer
Results are estimates for planning and ordering. They are not engineering advice. For structural work, follow your local building code and consult a qualified professional.