Concrete Footing Calculator
Concrete for footings & foundation trenches
Pouring strip footings or a foundation trench? Enter the footing length, width and depth to get the concrete required in cubic yards and bags.
Sizing a footing
Treat the footing as a long box: length × width × depth. For multiple identical footings, set the "number of areas" field. Local codes dictate minimum footing size, so always check before you dig.
Don't run short
Footings are structural — a cold joint from running out mid-pour is a real problem. Order 10% extra.
Frequently asked questions
How deep should a footing be?
Below the local frost line — often 12–48 inches depending on climate. Check your building code.
Bags or ready-mix for footings?
Small post footings can be bagged; continuous foundation footings are almost always ready-mix.