FC

Concrete Wall Calculator

Figure cubic yards for foundation walls and stem walls by the linear foot. Enter wall length, height, and thickness — get yards, bag counts if you are hand-mixing, and an ordering number with waste already built in.

Concrete Wall Calculator

The live calculator embeds here. Enter your dimensions to get cubic yards, bag counts, and cost in seconds.

Open the Calculator

The basics

How the calculator works

  • 1

    Convert thickness to feet

    Divide the wall thickness in inches by 12. An 8" wall is 0.667 ft, not 8 — this is the step most people skip and the most common reason a wall pour comes up short.

  • 2

    Enter length and height

    Give it the total linear footage of wall and the height from top of footing to top of wall. Type the numbers the way you read them off the print.

  • 3

    Subtract large openings

    Knock out big blockouts like walkout doors and basement windows. Small pipe sleeves get covered by the waste factor.

  • 4

    Add waste and order

    Default 8–10% covers form deflection and overfill at the top course. The calculator rounds to the way the plant takes the order.

Show the math

The formula

Cubic Yards = (Length ft × Height ft × Thickness ft) ÷ 27

Walls are a three-dimensional run, so convert the thickness from inches to feet first (8 in = 0.667 ft), multiply length × height × thickness for cubic feet, then divide by 27 for cubic yards. Add 8–10% on formed walls because forms bow slightly under load and you overfill the top.

Worked example

120 linear feet of 8-inch foundation wall, 8 feet tall.

  1. 1.8 in ÷ 12 = 0.667 ft thickness
  2. 2.8 ft × 0.667 ft = 5.34 sq ft cross-section
  3. 3.5.34 × 120 = 640.8 cubic feet
  4. 4.640.8 ÷ 27 = 23.7 cubic yards
  5. 5.23.7 × 1.10 (10% waste) = ~26 cubic yards

Order about 26 cubic yards of ready-mix.

20+ years in the field

Real contractor tips

Never come up short on a wall

Running out mid-pour creates a cold joint, which is a structural problem on a foundation wall. Order long — leftover concrete is cheaper than a second truck and a horizontal seam.

Pour the footing separately

The footing under the wall is usually a different mix and a different day. Calculate it on its own and add the two numbers — do not lump them together.

Watch your form height

Crews routinely overfill the top course to screed it off. That overfill is real volume, which is exactly why walls get an 8–10% factor instead of slabs-grade 10%.

Check the thickness against the plan

Stem walls and frost walls are often 6" or 10", not the 8" you assume. One wrong thickness across 120 feet is several yards off.

Avoid these

Common mistakes contractors make

  • Using the wall thickness in inches without converting to feet.
  • Forgetting to subtract large door and window blockouts.
  • Lumping the footing volume in with the wall volume.
  • Skipping the waste factor and getting a cold joint.
  • Assuming 8" thickness when the print calls for 6" or 10".
  • Measuring wall height to the wrong reference instead of top of footing.

Versus typical concrete calculators

  • Built for linear-foot wall runs, not just a single rectangle.
  • Keeps inch-to-foot thickness conversion straight for you.
  • Lets you subtract openings instead of over-ordering.
  • Applies a wall-specific waste factor automatically.
  • Saves the wall alongside the footing under one job.

Versus heavy takeoff software

  • No desktop install or license seat to pour a wall.
  • Works on your phone at the form line.
  • Free to start with no per-project pricing.
  • Focused on concrete instead of a full estimating suite.
  • Open it and order today, not after onboarding.

Frequently asked questions

For large blockouts, yes — a 3x6 ft basement window or a walkout door removes real volume. For small penetrations like pipe sleeves, do not bother; the waste factor covers them.

Stop guessing yardage on the back of a napkin

Run your next pour through the calculator, save the job, and keep every area in one place. Free to start.

Open the App