Skip to content
CostToUpgrade
CalculatorsCost GuidesCost DataMethodology Search Browse calculators
Concrete

Concrete Footing Calculator

Estimate the concrete in a continuous strip footing — the poured trench that carries a foundation wall, garage slab edge, or block wall. Enter the total run in feet plus the footing width and depth in inches to get cubic yards to order, 80 lb bag count for small pours, and a material cost.

Reviewed by The CostToUpgrade Estimating Desk Last reviewed How we estimate

Your project

Dimensions

Add up every leg of the trench — a 20 × 10 ft addition is 60 linear feet.

Common rule: twice the wall width, so an 8" wall sits on a 16" footing.

The IRC minimum footing thickness is 6"; 8–12" is typical residential.

Trenches never come out to size — 10% is standard, 15% in loose soil.

Pricing

Delivered ready-mix commonly runs $140–$190 per cubic yard before fees.

Estimate

2.17yd³

Concrete needed · Includes waste — round up to the next ¼ yard when ordering

Volume
58.7ft³
80 lb bags (small pours)
98bags
Estimated concrete cost
$358.52

Estimates are guidance only and exclude tax, labor, and site conditions unless stated. Confirm with a local pro.

How it's calculated

No black boxes — here is the exact math behind your estimate, so you can check it or adapt it for your own quote.

  1. 1Volume (ft³) = run × (width ÷ 12) × (depth ÷ 12)
  2. 2Volume with waste = volume × (1 + over-dig% ÷ 100)
  3. 3Cubic yards = volume with waste ÷ 27
  4. 4Bags (80 lb) = ⌈ volume with waste ÷ 0.6 ⌉
  5. 5Cost = cubic yards × price per cubic yard

Worked example

A 60 ft perimeter footing 16 inches wide and 8 inches deep with a 10% over-dig allowance.

Inputs

Total footing run
60 ft
Footing width
16 in
Footing depth
8 in
Over-dig allowance
10 %
Ready-mix price
165 $/yd³

Result

Concrete needed
2.17 yd³
Volume
58.7 ft³
80 lb bags (small pours)
98 bags
Estimated concrete cost
$358.52

Tools & materials for this project

As an Amazon Associate we may earn from qualifying purchases, at no extra cost to you.

  • Rebar chairs Hold footing steel up off the dirt so it gets full concrete cover.
    View on Amazon
  • Steel form stakes Pin footing forms to grade so they hold line during the pour.
    View on Amazon
Get real quotes

Compare local pros for concrete footings

An estimate gets you a budget. A few competing quotes get you the real price. Tell us about the job and we'll help you find vetted contractors nearby.

Get matched

Concrete Footing cost by state

The calculator does the quantity math exactly. What it can't know is what a fair unit price looks like where you live — concrete footings runs 61% more in the priciest US market than the cheapest.

Concrete Footing cost in all 50 states + DC US average $165 per cubic yard delivered · regional averages, full ranked table, and typical project totals.

Frequently asked questions

How wide and deep should a concrete footing be?
The long-standing residential rule is a footing twice the width of the wall it carries, and at least as thick as the amount it projects past that wall. An 8-inch foundation wall therefore gets a 16-inch-wide footing 8 inches thick. The IRC sets 6 inches as the minimum footing thickness. Prescriptive tables widen the footing as loads grow and soil weakens — two-story walls or 1,500 psf soil often push you to 20–24 inches wide. These are planning figures only: your local building department and, where required, a licensed engineer set the actual size.
Does local code decide my footing size?
Yes, on two counts. First, frost depth: the IRC requires footings to bear below the local frost line and at least 12 inches below undisturbed ground. That is effectively 0 inches in south Florida, 18–24 inches through much of the mid-Atlantic, and 42–48 inches in northern Minnesota and New England. Second, soil bearing capacity: the IRC default presumptive value is 1,500 psf for clay and silty soils, rising to 2,000–3,000 psf for sand and gravel. Weak soil means a wider footing. Treat this calculator as a volume estimate, not a structural design.
Why order about 10% extra concrete for footings?
Footing trenches are dug by machine or by hand into dirt, not built to a form, so the real hole is always bigger than the drawing. Sidewalls slough in, the bottom is uneven, and the bucket cuts wide at corners. Ten percent covers that on formed or clean-cut trenches; 15% is safer for hand-dug trenches in sand or loose fill. Running short mid-pour is far worse than having a wheelbarrow left over, because a cold joint in a footing is a permanent weak point. Round the final number up to the next quarter yard.
Should I use bagged concrete or order ready-mix for a footing?
One cubic yard equals 45 80-lb bags, and at roughly $5–$7 a bag that is $225–$315 in material versus about $165 per yard delivered. Bags make sense under roughly half a yard — a short pier line or a repair. Beyond about one yard, ready-mix is cheaper and far faster, even after a short-load fee (commonly $50–$150 on orders under 3–4 yards). A continuous footing also wants to be placed in one go; hand-mixing 50-plus bags almost guarantees cold joints between batches.
Does a footing need rebar?
Most jurisdictions require continuous horizontal steel in a footing — commonly two #4 bars run the length of the trench, held about 3 inches up off the earth on chairs or dobies, with corner bars bent to tie the legs together. Laps are typically 20 inches or more for #4 bar. Some areas also require vertical dowels from the footing into the wall above. Steel is not included in this estimate; size and placement are set by local code and the approved plans, so confirm with your inspector before you pour.

Related calculators

Concrete

Concrete Slab Calculator

Open calculator

Concrete

Rebar Calculator

Open calculator

Concrete

Concrete Cost Calculator

Open calculator

Concrete

Asphalt Driveway Calculator

Open calculator