Square Feet to Cubic Yards Calculator
Already know your area? Enter square feet and depth to convert straight to cubic yards and cubic feet.
This is the shortcut version of the standard gravel formula — useful if you already have a square footage from a landscaper's quote, a floor plan, or a property listing, and don't want to re-measure length and width separately.
Area stays in square feet either way — only the depth unit toggles.
The Conversion Formula
Convert depth to feet, multiply by your area to get cubic feet, then divide by 27 to get cubic yards.
cubic yards = cubic feet ÷ 27
The division by 12 turns your depth from inches into feet, since area is in square feet — mixing units is the single most common mistake people make converting this by hand.
Quick Conversion Table
| Depth | Sq ft per cubic yard | Cubic yards per 100 sq ft |
|---|---|---|
| 1 in | 324 sq ft | 0.31 yd³ |
| 2 in | 162 sq ft | 0.62 yd³ |
| 3 in | 108 sq ft | 0.93 yd³ |
| 4 in | 81 sq ft | 1.23 yd³ |
| 6 in | 54 sq ft | 1.85 yd³ |
Worked Example
Say you're ordering pea gravel for a 300 sq ft patio at a 3-inch depth. Convert 3 inches to feet: 3 ÷ 12 = 0.25 ft. Multiply by area: 300 × 0.25 = 75 cubic feet. Divide by 27: 75 ÷ 27 ≈ 2.78 cubic yards — call it 3 cubic yards once you add a little for waste. At pea gravel's typical density of 1.4 tons per cubic yard, that's roughly 3.9 tons to order from your supplier. Change the area or depth above to run the same steps on your own project.
A second example at a larger scale: a contractor quotes a 1,200 sq ft gravel driveway at a 4-inch depth. That's 4 ÷ 12 = 0.33 ft, so 1,200 × 0.33 = 400 cubic feet, or 400 ÷ 27 ≈ 14.8 cubic yards — call it roughly 22 tons of crushed stone at 1.5 tons/yd³. Knowing the shortcut means you can sanity-check a supplier's quote in your head before you ever pick up a tape measure.
What Is a Cubic Yard?
A cubic yard is a cube 3 feet on every side — 27 cubic feet — and it's the standard unit gravel, mulch, sand, and topsoil are priced and delivered in, since it lines up with typical dump-truck and loader capacities. Square feet measures a flat area; cubic yards measures volume, which is why depth has to enter the calculation at all — the same 300 sq ft patio needs roughly four times as much material at an 8-inch depth as it does at 2 inches, even though the footprint on the ground never changes. For more on how cubic yards convert to weight by material, see the cubic yards calculator.
Frequently asked questions
How do I convert square feet to cubic yards?
Multiply your area in square feet by your depth in feet (inches ÷ 12) to get cubic feet, then divide by 27. Example: 300 sq ft at 3 inches deep = 300 × 0.25 ÷ 27 ≈ 2.78 cubic yards.
How many square feet does a cubic yard cover?
One cubic yard covers about 324 square feet at 1 inch deep, 162 square feet at 2 inches, or 108 square feet at 3 inches — see the table above for more depths.
Do I need to know cubic feet before I can find cubic yards?
No — cubic feet is just an intermediate step in the math. Area (sq ft) × depth (ft) gives cubic feet, and dividing that by 27 gives cubic yards directly. The calculator above skips straight from your inputs to the final cubic yard figure.
Why divide by 12 for depth?
Depth is usually measured in inches, but area is in square feet, so the units have to match before multiplying. Dividing inches by 12 converts to feet — for example, 3 inches ÷ 12 = 0.25 feet.