About

Our mission is to help people estimate building materials with numbers they can inspect and adjust. Most material calculators hand back a number without the reasoning. When it looks wrong, you need to see whether the tool used a different depth, material weight, or waste allowance.

These calculators show the arithmetic every time: the area, the volume, the waste allowance, the conversion, and the weight assumption used to turn cubic yards into tons. Every constant is listed onhow we calculate, with the range it realistically varies over, and you can change it on the calculator when your supplier quotes something different.

Everything runs in your browser. There is no account, nothing is stored, and no measurement you type is sent anywhere.

Corrections

If a figure looks off, the fastest fix is a specific one: which calculator, what you entered, what you expected, and the source you are comparing against. Supplier product sheets and manufacturer bag data beat rules of thumb, and any correction gets reflected on the how we calculate page.

We publish the assumptions and source notes so you can check our work. Use the contact page or email [email protected] with an example and source. About page reviewed October 8, 2026.

Limits

This is quantity estimating for planning and ordering. It is not structural design. Slab thickness for a load, reinforcement, drainage and frost depth are decided by local code and, where it matters, a qualified engineer.