Square Feet to Cubic Yards Calculator — ft² + depth → yd³
Find how many cubic yards of concrete, gravel, mulch or topsoil you need: enter the area in square feet and the depth/thickness in inches. The calculator gives cubic yards, cubic feet, cubic metres and a rounded-up order quantity.
ft²
inches
Volume = Area (ft²) × Depth (in) ÷ 324
2.47 yd³
volume- 1
Depth in feet
4 ÷ 12 = 0.333333 - 2
Volume in cubic feet
200 × 0.333333 = 66.67 - 3
Cubic yards
66.67 ÷ 27 = 2.47One cubic yard = 27 cubic feet (3 ft × 3 ft × 3 ft).
How does this calculator work?
Cubic yards = area (ft²) × depth (in) ÷ 324. For example, a 200 ft² patio at 4 in of concrete needs 200 × 4 ÷ 324 ≈ 2.47 yd³. Common uses: concrete slabs, gravel paths, mulch beds, topsoil fill. Order the rounded-up value shown to allow for waste.
Formula
How this is calculated
To find the volume of a flat slab of material, multiply its area by its thickness. With area in square feet and thickness in inches, first convert inches to feet (divide by 12) to get volume in cubic feet: Volume (ft³) = Area (ft²) × Depth (in) / 12. Then convert cubic feet to cubic yards by dividing by 27 (since 1 yard = 3 feet → 1 yd³ = 3³ = 27 ft³). Combining both steps gives the shortcut: Volume (yd³) = Area (ft²) × Depth (in) / 324.
Cubic yards are the standard ordering unit for bulk materials in the United States and Canada: concrete, crushed stone, pea gravel, topsoil, mulch, sand and fill dirt are all typically sold by the yard. A single cubic yard fills a cube that is 3 ft × 3 ft × 3 ft and weighs roughly 1.35 tonnes for concrete, 1.4 tonnes for gravel and about 0.8 tonnes for dry mulch — check the weight capacity of your vehicle before ordering.
The calculator also rounds the result up to the nearest quarter cubic yard, which is how most suppliers price and quote material. Common depth rules of thumb: mulch and bark chips 2–3 inches, decorative gravel 3–4 inches, concrete slabs 4 inches, driveways 6 inches and topsoil or garden beds 6–8 inches. If your project has an irregular shape, break it into rectangular sections, calculate each, and add the results.
Frequently asked questions
10 × 10 = 100 ft² × 4 in ÷ 324 ≈ 1.23 yd³. For concrete you would typically order 1.5 yd³ to allow for waste and spillage.
Concrete ≈ 2 tonnes (4,050 lb), compacted gravel ≈ 1.4 tonnes (3,000 lb), dry wood mulch ≈ 0.4–0.7 tonnes (800–1,400 lb). Always check vehicle payload limits before loading.
Yes — divide the space into simpler rectangles or use the area formula for your shape (e.g. circle = π r²), compute the area in square feet, then enter it here. For irregular shapes, a rough sketch split into rectangles is usually accurate enough for ordering.
Also known as
TG we-Calculate Editorial Team. (2026). Square Feet to Cubic Yards Calculator — ft² + depth → yd³ [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/ft2-yd3-calculator
TG we-Calculate Editorial Team. "Square Feet to Cubic Yards Calculator — ft² + depth → yd³." TG we-Calculate. 2026. https://we-calculate.com/calculator/ft2-yd3-calculator.
TG we-Calculate Editorial Team, "Square Feet to Cubic Yards Calculator — ft² + depth → yd³," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/ft2-yd3-calculator
@misc{wecalculate_ft2_yd3_calculator, title = {Square Feet to Cubic Yards Calculator — ft² + depth → yd³}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/ft2-yd3-calculator}}, year = {2026}, note = {TG we-Calculate} }
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