Concrete Depot Concrete Calculators & Tools

Concrete Footing Size Calculator

Estimate the required footing footprint from load and soil bearing capacity, then calculate footing depth, concrete volume, bags, and cost.

Measurement inputs

Live calculation updates as you type.

Size + volume
Used in the saved report.
Changes starter units only.
Shape changes the size formula.
Use a soil report or local code value when available.
Use centered service load for one footing. Enter a load greater than 0.
Do not guess for structural design. Enter a soil bearing value greater than 0.
Used for continuous wall footings. Enter a total length greater than 0.
For rectangular pad footing only. Enter a ratio of 1 or more.
This is concrete thickness, not frost depth. Enter a depth greater than 0.
Number of identical footings. Enter at least 1.
Rounds the recommended footing size up.
Use 1.00 unless plans say otherwise. Enter a multiplier of 1 or more.
Use 5–15% for most estimates. Waste cannot be negative.
Optional material-only estimate. Cost cannot be negative.

Live 3D footing preview

The same SVG is used in the report.

Square pad
Footprint —
Bearing area —
Depth —
Recommended footing size
—

Enter values to calculate a footing size.

For planning only. Final footing size may be controlled by local code, frost depth, settlement, eccentric load, shear, flexure, reinforcement, uplift, sliding, or engineered plans.
Required bearing area—
Actual bearing pressure—
Base concrete—
Order with waste—
60 lb bags—
80 lb bags—
Estimated material cost—
Concrete weight—
Volume in cubic feet—
Formula used
Required area = Load ÷ Allowable soil bearing

All loads and soil bearing values are converted to pounds and psf before sizing.

Calculation steps
  1. Enter valid measurements to see the steps.