Retaining Walls

Concrete Retaining Wall Calculator

Enter your wall's length, height, and thickness \u2014 with an optional footing \u2014 to get total cubic yards and cost.

The Retaining Wall Calculator helps you figure out exactly how much material to buy before you order a truck or make a hardware store run. Enter your wall's length, height, and thickness \u2014 with an optional footing \u2014 to get total cubic yards and cost. Instead of guessing at cubic yards or bag counts and hoping it's close, you enter the numbers you already have — the measurements from your plan, tape measure, or job site — and get a precise, ready-to-order figure back in seconds.

This tool is built for two kinds of people: contractors running a fast takeoff between jobs who need a number they can call into a supplier immediately, and homeowners or first-time DIYers who don't want to either overspend on wasted material or come up short mid-pour. Every calculator on ConcreteYard uses the same standard, industry-typical assumptions — 150 lb per cubic foot for normal-weight concrete, standard bag yields, and common mix ratios — so the numbers here should line up closely with what your supplier or hardware store confirms when you place the order.

Whether you're pricing out a job, planning a delivery, or just want to know how much to buy at the store today, this calculator gives you a number you can act on immediately — no spreadsheet, no account, and no guesswork required.

Retaining Wall Dimensions

Walls over ~3\u20134 ft or holding back significant slope should be engineer-reviewed \u2014 this is a material estimate, not a structural design.

Calculated
Wall TicketCC-000000-000
Wall Volume0 cu ft
Footing Volume0 cu ft
Total With Waste0 cu ft
Est. Cost—
Order This Many Yards0.00 yd³
Standard footing assumed at 2x wall thickness wide by 12in deep \u2014 adjust for your soil and engineer's spec.

How to Use the Retaining Wall Calculator

1. Measure accurately. Get exact dimensions in the units the calculator asks for — feet for length and width, inches for thickness are the most common setup. A rough guess in, a rough number out; precise measurements are what make this tool worth using over a mental estimate.

2. Enter your numbers. Fill in the fields above with your project's actual measurements. Default values are pre-filled as a sane starting point — replace every one of them with your real numbers before you rely on the result.

3. Adjust the settings. Where available, set your waste percentage, bag size, or price per yard to match your job. These small adjustments are what separate a rough ballpark from an order-ready figure.

4. Read the batch ticket. Click calculate and use the highlighted total as your order quantity — it already accounts for waste and rounds to a practical ordering increment where relevant.

Retaining Wall Thickness by Height

Wall HeightTypical Thickness
Under 3 ft6\u20138 in
3\u20134 ft8\u201310 in
Over 4 ftEngineer-designed

When You Need an Engineer

Most jurisdictions require a permit and engineered design for retaining walls over 3\u20134 ft, or any wall holding back a slope with a structure (house, driveway) above it. This tool estimates material only.

Frequently Asked Questions

How much concrete does a retaining wall need?

Multiply the wall's length, height, and thickness (in feet) for wall volume, then add footing volume if poured. This calculator includes an optional standard footing at twice the wall thickness.

Do I need a permit for a concrete retaining wall?

Many areas require a permit and engineered design for walls over 3-4 feet tall, or shorter walls holding back significant load. Check your local building department before pouring.

Common Estimating Mistakes to Avoid

Skipping the waste factor. Uneven subgrade, formwork gaps, and simple spillage routinely eat 5–10% of your raw calculated volume. Ordering the exact math-perfect number is one of the most common ways to come up short mid-pour.

Rounding down instead of up. Ready-mix trucks deliver in fractions of a yard, but suppliers set order minimums. If your number lands at 4.1 yards, round to 4.25 or 4.5, not down to 4.

Mixing up units. Thickness is almost always in inches while length and width are in feet — plugging inches into a feet field (or vice versa) is the single most common calculator input error.

Treating irregular shapes as one rectangle. An L-shaped or curved area isn't one simple calculation. Break it into rectangles, run each section separately, and add the totals together for an accurate figure.

Tips for a Successful Pour

Order slightly more than the bare minimum — a short-load fee for a second truck almost always costs more than the extra material would have. Confirm your supplier's order minimum and short-load fee before you finalize a quantity that's close to the cutoff.

Check the weather. Concrete needs temperatures generally above 40°F to cure properly without special cold-weather additives, and pouring in direct heat or high wind can cause the surface to dry and crack before it has a chance to properly set.

Have everything staged before the truck arrives — forms set, base compacted, tools (screed board, bull float, edger) on site, and enough hands to place and finish the pour before it starts to set.

Plan your control joints in advance for any flatwork. Joints control where concrete cracks as it cures and shrinks — skipping them doesn't prevent cracking, it just makes the cracks unpredictable.

More Questions

Is this calculator accurate?

Yes — it uses standard, industry-typical formulas and material assumptions (150 lb/cu ft concrete, standard bag yields, common mix ratios). For structural or permitted work, always confirm final quantities with your supplier or engineer.

Do I need to create an account to use this?

No. Every calculator on ConcreteYard runs entirely in your browser, works instantly, and requires no sign-up, login, or download.

Can I use this calculator on my phone at the job site?

Yes — every tool on this site is built to work the same on a phone as it does on a desktop, so you can run the numbers standing at the job site before you call in an order.

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