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concrete

Concrete Footing Calculator

Estimate concrete yards and bags for continuous strip footings. Results update instantly as you change the inputs.

Start estimate Read FAQs
Output
yards / bags / cost
Mode
planning estimate
Concrete Footing Calculator estimating scene A construction estimating worksheet with concrete forms, bag count notes, a tape measure, and supplier order math. ORDER 2.61 yd3 80 lb live order math waste + rounding
live order math 2.61 yd3

Enter length and width in feet, thickness in inches.

Use Area when you already know square footage. Ramp uses different start and end thicknesses.

Quick estimates
Component templates

Suggested waste for this setup: 10-15%. Trenches, walls, and formwork often vary more than flat slabs.

Cost planning uses the selected order unit. Delivery, short-load fee, and labor are extra.

Advanced cost

Labor range uses $4-$8 per ft² as a planning range.

Multi-section estimate

Add irregular areas, aprons, landings, or pads and BuilderCalc will total them.

Estimated concrete neededEnter dimensionsLength, width, and thickness are required before the estimate appears.
Example40 ft footing x 2 ft wide x 10 in = about 2.47 yd³

Check local footing width, frost depth, and code requirements before ordering.

Last reviewed: May 12, 2026 by the BuilderCalc editorial team.

Footing planning

Concrete Footing Calculator planning notes

Footings are code-sensitive work. Use the calculator to estimate volume, then confirm width, depth, frost requirements, soil conditions, and reinforcement before ordering.

Measure the trench after excavation

Plan dimensions are a starting point, but real trenches often get wider or deeper during digging. Measure formed or excavated width, depth, and total run before finalizing the order.

Keep frost depth separate from volume

The calculator estimates concrete quantity. It does not decide bearing capacity, frost protection, or footing design. Those requirements come from local code and site conditions.

How to use it

Keep the estimate tied to field measurements

01

Measure trench dimensions

Use the actual excavated or formed length, width, and depth. Real trenches often differ from plan dimensions.

02

Check code requirements

Confirm frost depth, bearing needs, reinforcement, and inspection requirements before treating the volume as final.

03

Order with waste

Add waste after measuring the trench so over-dig, rough edges, and form variation are covered.

Related calculators

Try the slab calculator Calculate concrete yards and bags for garage slabs, shed bases, pads, and flatwork. Need sidewalk concrete? Calculate concrete for sidewalks, walkways, and narrow slab pours. Estimating a driveway? Estimate ready-mix concrete and bag counts for a residential driveway slab.
Estimate wall concrete Estimate concrete yards for wall pours using length, height, and thickness. Calculate stair concrete Estimate concrete for solid stair pours using width, tread depth, riser height, and step count. Round columns and piers Calculate concrete volume for round columns and piers. Add reinforcement planning Estimate rebar sticks for a rectangular reinforcement grid.
Need bag counts instead? Convert slab dimensions into 40 lb, 60 lb, and 80 lb concrete bag counts. Convert to cubic yards Calculate cubic yards of concrete from project dimensions. Work in cubic feet Calculate concrete cubic feet, cubic yards, and cubic meters.

FAQ

Concrete estimating questions

How do I calculate concrete for a footing?

Multiply footing length by width by depth, all in feet, then divide cubic feet by 27 to get cubic yards. Add waste after measuring the excavated or formed trench.

What size footing should I use?

Footing size depends on load, soil bearing, frost depth, and local code. The calculator estimates volume only; it does not size a structural footing.

Should footing depth include frost depth?

The volume should include the actual concrete depth being poured. Whether the footing must extend below frost depth is a local code and design question.

Do footings need rebar?

Many continuous footings use reinforcement, but bar size and spacing depend on the design. Confirm the layout before ordering concrete.