About SizeMyProject
Free, fast calculators that answer the question every project starts with: how much do I need to buy?
Why this site exists
Most of the time wasted on a DIY project happens before the work starts: working out cubic yards in your head in the aisle, guessing how many bags go into a slab, or ordering a truckload of gravel that turns out to be two tons short. SizeMyProject turns your measurements into a clear shopping list — in the units stores and suppliers actually sell — and shows the math behind every number.
Who's behind it
SizeMyProject is an independent project built and run by Daniel, who also makes free online tools for creators. It isn't owned by a manufacturer or a retailer, and no brand pays to be mentioned in our results.
How we write and check our pages
Each calculator is built from the underlying geometry and from published reference data, such as manufacturer data sheets and university extension guidance. Pages are researched and drafted with the help of AI tools, then the formulas are checked by hand against worked examples before anything is published. Each page lists its sources and the date it was last updated. Read how we calculate for the details.
We aren't contractors or engineers, and we say so. Our calculators estimate quantities; they don't replace your plans, your local building code or a professional's advice on structural work.
How the site is funded
The calculators are free to use. In the future the site may show advertising to cover its costs. Advertising will never change the numbers a calculator gives you.
Get in touch
Spotted a mistake, need a calculator we don't have yet, or want to suggest a better source? Write to hello@sizemyproject.com. See also our contact page.