Get a useful result
- Replace the example dimensions with your measurements. Choose a rectangle or circle.
- Choose length and depth units independently. Use decimal values such as 2.5, not a feet-and-inches expression.
- Enter the actual quantity per bag. Leave density blank for a volume-only estimate.
- Open the options only if you need a supplied multiplier, a buffer, mass or a price estimate.
- Calculate again after edits. Save each distinct section to your shared shopping list before entering another.
Why did I get another bag?
Whole bags round up from the unrounded order requirement. A result displayed as 1.000 m³ might be slightly greater than one cubic metre internally. Lowering display precision does not reduce the material needed. Check your depth and the label on the bag.
Printing and saving a PDF
Use “Print this estimate” for the current result, or add several estimates then use “Print shopping list”. In the browser dialog, choose your printer or Save as PDF. A4 and US Letter layouts omit the site navigation and forms. Browser-added headers/footers are controlled by your print dialog. Shopping lists are saved in this browser across visits and calculators. Clear the list when you are finished, especially on a shared device.
Weight is missing
This is intentional when no density is entered. Ask the supplier for the loose bulk density of the delivered material. A mass bag or mass-based price cannot be converted to volume without a compatible density.
Contact the owner
Send Rob a question, correction or privacy request. Product suitability and delivery questions belong with your supplier. Please omit sensitive information. Your message goes through Resend to the owner’s private inbox; read how it is handled.
If a calculation looks wrong
Keep the page URL, dimensions and units, bag size, selected allowances, expected result and a screenshot for a correction report. Do not include personal information in a shopping-list label you plan to share. For product-specific quantities, contact your supplier directly.
For the formulas and source definitions, read our calculation method.