About The Block Calculator

Last updated: September 24, 2026

The Block Calculator is a free collection of masonry and construction calculators. It helps homeowners, DIYers, contractors and students estimate block quantities, core fill, weight and material costs before they buy.

What we do

Each calculator uses a published, transparent formula that is shown on the page, with a worked example so you can check the maths yourself. Everything runs in your browser. The numbers you enter are not sent to our servers.

How we keep results reliable

• Every formula and example is shown in full on its calculator page.
• Results are always rounded up, so you are not left short of materials.
• We review the calculators and their content regularly and show a “Last updated” date on each page.

Important note

Our tools give estimates for planning. They are not a substitute for professional engineering, local building codes or supplier specifications. Please read our disclaimer.

Get in touch

Found a bug, or want a new calculator? Contact us. We read every message.