March 28, 2026
We checked the calculator logic, page links, and support content used on this page.
Estimate footing concrete volume, order quantity, and rough cost for trench and strip foundations.
We checked the calculator logic, page links, and support content used on this page.
Use this calculator to build a rough material estimate, then confirm the final order against product data and site conditions.
Read the calculator methodology and editorial policy for the standards behind these pages.
Volume calculators assume the job can be reduced to length, width, depth, and a practical density or buying-unit conversion.
Depth mistakes are the biggest problem, followed by using the wrong density and forgetting that loose and compacted materials do not behave identically.
Best for aggregates, soils, screeds, and fill materials where the order usually starts with volume, then converts into tonnes, bags, or bulk units.
Check whether the depth entered is the installed depth or the loose-delivered depth, because the difference can materially change the order.
Bag and bulk pricing can diverge quickly once the quantity grows, so use the output to compare the real delivered buying route, not just a headline unit cost.
UK and US buyers often use different unit language and pack conventions, but the geometry, waste, and whole-unit rounding logic are still the foundation.
Before placing an order, compare the assumed depth, density, buying-unit size, delivery access, and whether bulk supply is more realistic than bagged buying.
Open the full Concrete Estimating tool set to move from quick estimate to deeper guidance.
Enter the measured dimensions and depth, choose a realistic waste setting, and use this calculator to compare the likely buying quantity before you choose bags, bulk, or tonnage-based supply.
The biggest drivers are the measured depth, the density or yield assumption, and whether the material is being bought loose, bulk, or bagged.
Bag and bulk pricing can diverge quickly once the quantity grows, so use the output to compare the real delivered buying route, not just a headline unit cost.