Concrete Yardage Calculator Guide
Use a concrete yardage calculator to convert length, width, thickness, waste, bags, ready-mix minimums, and delivery fees into cubic yards.
Quick answer
10x10 = 1.36 yd3
4 in slab with 10% waste; 12x12 = 1.96 yd3 and 20x20 = 5.43 yd3
A concrete yardage calculator answers the question most U.S. suppliers ask before pricing ready-mix: how many cubic yards do you need? The useful answer does not stop at length x width x thickness. It also needs waste, bag fallback, minimum-load exposure, delivery fees, access, and quote scope.
Use the Concrete Volume Calculator for the fastest multi-shape yardage result. Use the Concrete Slab Calculator for patios, shed bases, driveways, and garage slabs, then compare the buying path in the Ready-Mix vs Bags Calculator.
This page targets the yardage wording without creating a duplicate
/concrete-yardage-calculator tool route. The canonical tool remains the
volume calculator because it can output cubic yards, cubic feet, cubic meters,
bags, waste, and cost in one workflow.
Quick answer
For a rectangular slab:
cubic yards =
length ft x width ft x thickness ft / 27
For a 4 inch slab, thickness is 0.333 ft. Add waste before ordering:
order yards = cubic yards x (1 + waste percent)
Common planning examples with 10% waste:
| Slab size at 4 in | Order yardage | 80 lb bags | Buying note |
|---|---|---|---|
| 10x10 | 1.36 yd3 | 62 bags | Check store delivery vs small ready-mix. |
| 12x12 | 1.96 yd3 | 89 bags | Usually quote ready-mix and bag fallback. |
| 20x20 | 5.43 yd3 | 245 bags | Ready-mix first. |
| 24x24 | 7.82 yd3 | 352 bags | Ready-mix first; check access and finish crew. |
Bag counts use a common 0.60 ft3 yield for 80 lb bags and are rounded up. Always check the actual bag yield and local supplier minimums.
Yardage calculator inputs
| Input | Why it matters | Where to check next |
|---|---|---|
| Length and width | Defines the project footprint. | Slab, driveway, patio, sidewalk, or pad calculator. |
| Thickness | A 4 in vs 6 in slab changes yards by 50%. | Written quote, plans, local rules, or engineer. |
| Waste factor | Covers uneven forms, spillage, and ordering cushion. | Usually 5-10% for planning, not a universal rule. |
| Shape | Rectangles, tubes, walls, and steps use different formulas. | Concrete Volume Calculator. |
| Ready-mix minimum | Small jobs may be billed above usable yards. | Supplier quote or minimum-delivery guide. |
| Bag fallback | Bags may win for tiny jobs but add labor and pickup weight. | Concrete Bag Calculator. |
| Access | Chute, wheelbarrow, buggy, or pump can change cost. | Truck access and wheelbarrow guides. |
If you already know the yardage, use the Concrete Cost Calculator to compare delivered ready-mix, bagged concrete, and material-only totals.
Yardage examples by project
These rows use a 10% waste factor and focus on material volume before prep, forms, reinforcement, finish, cleanup, permits, or contractor overhead.
| Project | Dimensions | Yardage with waste | Good next page |
|---|---|---|---|
| Small pad | 6x8 x 4 in | 0.65 yd3 | Concrete Trash Pad Cost |
| Patio | 12x12 x 4 in | 1.96 yd3 | Concrete Patio Calculator Guide |
| Sidewalk | 40x4 x 4 in | 2.18 yd3 | Concrete Sidewalk Cost Calculator |
| Driveway slab | 20x20 x 4 in | 5.43 yd3 | 20x20 Concrete Slab Cost |
| Garage slab | 24x24 x 4 in | 7.82 yd3 | 24x24 Garage Slab Cost |
For thickness changes, multiply the 4 inch result by the new thickness divided by 4. A 6 inch version of the same slab uses about 1.5 times the concrete.
Yardage vs delivered total
The yardage number is not the same as the delivered invoice. Ready-mix quotes can include minimum billable yards, delivery, short-load, fuel, tax, wait time, and access charges.
| Yardage result | Pricing risk | What to ask |
|---|---|---|
| Under 1 yd3 | Bags, mini-mix, or a high minimum-load invoice. | What is the minimum delivered total? |
| 1-2 yd3 | Short-load fees may dominate. | Are unused paid yards included in the bill? |
| 3-5 yd3 | Ready-mix often becomes practical. | What delivery, wait time, and access terms apply? |
| 5+ yd3 | Crew timing and finish capacity matter. | Can the crew place and finish before set time? |
For small orders, compare the Minimum Concrete Delivery Order Guide and Concrete Short Load Fee Guide before approving a supplier quote.
Yardage quote worksheet
| Quote line | Supplier A | Supplier B | Notes |
|---|---|---|---|
| Calculated usable yd3 | Measured dimensions before waste. | ||
| Waste or order cushion | Who decides the final order amount? | ||
| Billable yd3 | Actual yardage or minimum billable load. | ||
| Price per yd3 | Mix strength and additives included. | ||
| Delivery and fees | Delivery, short-load, fuel, tax, environmental. | ||
| Access method | Chute, wheelbarrow, buggy, pump, or bucket. | ||
| Wait time included | Minutes included and rate after that. | ||
| Written delivered total | Compare total invoice, not only price per yard. |
Use the Concrete Local Cost Estimator when you have supplier numbers and want to compare delivered totals by usable yard.
FAQ
How do I calculate concrete yardage?
Multiply length by width by thickness in feet, then divide cubic feet by 27 to get cubic yards. Add waste before ordering.
How many yards are in a 10x10 slab at 4 inches?
A 10x10 slab at 4 inches is about 1.23 yd3 before waste or 1.36 yd3 with 10% waste. That is about 62 common 80 lb bags with waste.
Is yardage different from cubic yards?
In ready-mix ordering, yardage usually means cubic yards. A supplier asking for "yards" is normally asking for cubic yards of concrete.
Should I round concrete yardage up?
Yes, but do it intentionally. Add a waste factor, then discuss final rounding with the supplier or contractor. Do not round down to make the quote look cheaper.
Can I use yardage to price a contractor bid?
Use yardage to check the material line. Installed bids also include prep, forms, reinforcement, placement labor, finish, cleanup, overhead, and warranty.
Next step
Calculate the yardage, compare the buying path, then ask suppliers for a written delivered total that includes minimums, delivery, access, wait time, tax, and short-load terms.
Quote planning next step
Turn this guide into a concrete buying check
Run the matching calculator, then compare ready-mix, bagged concrete, delivery fees, access needs, and quote gaps before you buy materials or approve a contractor number.