Square Feet to Cubic Yards Calculator
Square Feet to Cubic Yards Calculator: Convert sq ft to cu yd Instantly
If you’ve ever ordered mulch, concrete, gravel, soil, or any bulk landscaping material, you’ve run into this problem: the area of your project is measured in square feet, but suppliers sell materials by the cubic yard. These are different types of measurements — one is area, the other is volume — and you can’t convert between them without one more piece of information: depth.
This guide explains exactly how the conversion works, gives you ready-to-use reference tables for mulch, gravel, concrete, and soil, and covers every common question about square feet to cubic yards.
Why You Can’t Convert Square Feet to Cubic Yards Without Depth
Square feet measure a flat area (length × width). Cubic yards measure volume (length × width × height). To go from one to the other, you must know how thick the material layer will be.
The formula is:
Cubic Yards = (Square Feet × Depth in Inches) ÷ 324
Where does 324 come from? One cubic yard = 27 cubic feet = 46,656 cubic inches. One square foot = 144 square inches. So 46,656 ÷ 144 = 324. That’s your conversion constant whenever depth is in inches and area is in square feet.
The Conversion Formula Explained
Step 1 — Measure your area in square feet
Area = Length (ft) × Width (ft)
Step 2 — Decide your depth in inches
Common depths:
- Mulch: 2–4 inches
- Gravel: 2–4 inches
- Concrete slab: 4–6 inches
- Topsoil: 3–6 inches
- Sand base: 1–2 inches
Step 3 — Apply the formula
Cubic Yards = (Area in sq ft × Depth in inches) ÷ 324
Example: Mulch for a 500 sq ft Garden Bed
You want 3 inches of mulch over 500 square feet:
(500 × 3) ÷ 324 = 1,500 ÷ 324 = 4.63 cubic yards
Round up to 5 cubic yards when ordering.
Square Feet to Cubic Yards Reference Tables
For Mulch and Topsoil (sq ft to cubic yards)
| Area (sq ft) | 2 inches deep | 3 inches deep | 4 inches deep | 6 inches deep |
|---|---|---|---|---|
| 100 sq ft | 0.62 cu yd | 0.93 cu yd | 1.23 cu yd | 1.85 cu yd |
| 200 sq ft | 1.23 cu yd | 1.85 cu yd | 2.47 cu yd | 3.70 cu yd |
| 300 sq ft | 1.85 cu yd | 2.78 cu yd | 3.70 cu yd | 5.56 cu yd |
| 500 sq ft | 3.09 cu yd | 4.63 cu yd | 6.17 cu yd | 9.26 cu yd |
| 1,000 sq ft | 6.17 cu yd | 9.26 cu yd | 12.35 cu yd | 18.52 cu yd |
| 1,500 sq ft | 9.26 cu yd | 13.89 cu yd | 18.52 cu yd | 27.78 cu yd |
| 2,000 sq ft | 12.35 cu yd | 18.52 cu yd | 24.69 cu yd | 37.04 cu yd |
For Concrete (sq ft to cubic yards)
Concrete is typically poured at 4 inches for slabs and 6 inches for driveways.
| Area (sq ft) | 3.5 inches (slab) | 4 inches (standard) | 6 inches (driveway) | 8 inches (heavy) |
|---|---|---|---|---|
| 100 sq ft | 1.08 cu yd | 1.23 cu yd | 1.85 cu yd | 2.47 cu yd |
| 200 sq ft | 2.16 cu yd | 2.47 cu yd | 3.70 cu yd | 4.94 cu yd |
| 500 sq ft | 5.40 cu yd | 6.17 cu yd | 9.26 cu yd | 12.35 cu yd |
| 1,000 sq ft | 10.80 cu yd | 12.35 cu yd | 18.52 cu yd | 24.69 cu yd |
| 1,500 sq ft | 16.20 cu yd | 18.52 cu yd | 27.78 cu yd | 37.04 cu yd |
For Gravel and Crushed Stone
Gravel is commonly ordered at 2–4 inches for paths and driveways, and up to 6 inches for structural base layers.
| Area (sq ft) | 2 inches | 3 inches | 4 inches | 6 inches |
|---|---|---|---|---|
| 100 sq ft | 0.62 cu yd | 0.93 cu yd | 1.23 cu yd | 1.85 cu yd |
| 250 sq ft | 1.54 cu yd | 2.31 cu yd | 3.09 cu yd | 4.63 cu yd |
| 500 sq ft | 3.09 cu yd | 4.63 cu yd | 6.17 cu yd | 9.26 cu yd |
| 1,000 sq ft | 6.17 cu yd | 9.26 cu yd | 12.35 cu yd | 18.52 cu yd |
How to Convert Square Feet to Cubic Yards: Step by Step for Common Projects
Square Feet to Cubic Yards for Mulch
Mulch is almost always applied at 2–4 inches. Deeper than 4 inches can suffocate plant roots; shallower than 2 inches won’t suppress weeds effectively.
Formula: (sq ft × depth in inches) ÷ 324
A 1,000 sq ft garden at 3 inches deep = (1,000 × 3) ÷ 324 = 9.26 cubic yards of mulch
One cubic yard of mulch covers approximately 108 sq ft at 3 inches or 162 sq ft at 2 inches.
Square Feet to Cubic Yards for Concrete
For concrete, contractors work in cubic yards and always add 10% for waste and overages.
Formula: (sq ft × depth in inches) ÷ 324 × 1.10 (with 10% buffer)
A 400 sq ft patio at 4 inches: (400 × 4) ÷ 324 × 1.10 = 5.43 cubic yards — order 5.5 cu yd.
Square Feet to Cubic Yards for Soil and Topsoil
Topsoil for a lawn is typically spread at 3–6 inches for new installations, or 1–2 inches for topdressing an existing lawn.
A 1,500 sq ft lawn raised bed at 4 inches: (1,500 × 4) ÷ 324 = 18.52 cubic yards of topsoil
Square Feet to Cubic Yards for Gravel
Driveways and paths use 3–4 inches of gravel; structural sub-bases use 4–8 inches.
A 600 sq ft driveway at 4 inches: (600 × 4) ÷ 324 = 7.41 cubic yards of gravel
Converting Cubic Yards Back to Square Feet
Sometimes you know how many cubic yards you have and want to know the area it will cover at a given depth. The reverse formula is:
Square Feet = (Cubic Yards × 324) ÷ Depth in Inches
Example: You have 5 cubic yards of mulch and want to spread it 3 inches deep:
(5 × 324) ÷ 3 = 1,620 ÷ 3 = 540 sq ft coverage
Cubic Yards to Tons Conversion
Many suppliers quote bulk materials in tons rather than cubic yards. The conversion depends on the material’s density:
| Material | Weight Per Cubic Yard | Cubic Yards Per Ton |
|---|---|---|
| Mulch (dry) | ~400–600 lbs | ~3.5 – 5 cu yd/ton |
| Topsoil | ~1,200–1,600 lbs | ~1.25 – 1.67 cu yd/ton |
| Sand | ~2,600–2,900 lbs | ~0.69 – 0.77 cu yd/ton |
| Gravel (#57) | ~2,800–3,000 lbs | ~0.67 – 0.71 cu yd/ton |
| Crushed limestone | ~2,700 lbs | ~0.74 cu yd/ton |
| Concrete (wet) | ~3,700–4,100 lbs | ~0.49 – 0.54 cu yd/ton |
When your supplier quotes in tons, divide your cubic yard estimate by the cubic yards per ton figure for that material to get your tonnage order.
How to Calculate Cubic Yards Without This Calculator
If you prefer to work through the math manually:
- Measure the area: length (ft) × width (ft) = sq ft
- Convert depth to feet: inches ÷ 12
- Multiply: sq ft × depth in feet = cubic feet
- Divide by 27: cubic feet ÷ 27 = cubic yards
Example: 200 sq ft at 4 inches (0.333 ft)
200 × 0.333 = 66.6 cubic feet 66.6 ÷ 27 = 2.47 cubic yards
Both methods — the ÷ 324 shortcut and the step-by-step ÷ 27 method — give identical results. Use whichever is faster for your situation.
Quick Reference: One Cubic Yard Coverage
| Material | 1 cu yd covers at 2″ | 1 cu yd covers at 3″ | 1 cu yd covers at 4″ |
|---|---|---|---|
| Mulch | 162 sq ft | 108 sq ft | 81 sq ft |
| Topsoil | 162 sq ft | 108 sq ft | 81 sq ft |
| Gravel | 162 sq ft | 108 sq ft | 81 sq ft |
| Sand | 162 sq ft | 108 sq ft | 81 sq ft |
| Concrete | 162 sq ft | 108 sq ft | 81 sq ft |
The coverage per cubic yard is the same for all materials at the same depth — because coverage is a geometry question, not a material question. The material type only matters when converting cubic yards to tons.
Frequently Asked Questions
How Many Sq Ft Is in a Cubic Yard?
This question can’t be answered with a single number because sq ft (area) and cubic yards (volume) measure different things. You need a depth to connect them. At 1 inch deep, 1 cubic yard covers 324 sq ft. At 3 inches deep, it covers 108 sq ft. At 6 inches deep, it covers 54 sq ft. The formula is: Coverage (sq ft) = 324 ÷ Depth (inches).
How Many Cubic Yards to Cover 1,000 Square Feet?
It depends on depth. At 2 inches: 6.17 cubic yards. At 3 inches: 9.26 cubic yards. At 4 inches: 12.35 cubic yards. At 6 inches: 18.52 cubic yards. Use the formula (1,000 × depth in inches) ÷ 324 to get the exact number for any depth.
How Many Cubic Yards Are in 500 sq ft?
Again, depth determines the answer. At 3 inches (common for mulch and topsoil): (500 × 3) ÷ 324 = 4.63 cubic yards. At 4 inches (concrete slab or gravel): (500 × 4) ÷ 324 = 6.17 cubic yards.
How to Calculate sq ft of a Pool?
For a rectangular pool, multiply length by width: a 16×32 pool = 512 sq ft of surface area. For an oval pool: (longer axis ÷ 2) × (shorter axis ÷ 2) × π. For irregular shapes, break the pool into rectangular sections and add the areas together. Note that pool surface area is different from pool volume — for pool water volume, you also need average depth.
How to Convert sq Feet into Cubic Yards?
Use the formula: Cubic Yards = (Square Feet × Depth in Inches) ÷ 324. Always confirm your depth in inches before calculating. If your depth is already in feet, use: Cubic Yards = (Square Feet × Depth in Feet) ÷ 27.
How Many sq ft Does 1 Cubic Yard of Mulch Cover?
One cubic yard of mulch covers 324 sq ft at 1 inch deep, 162 sq ft at 2 inches deep, 108 sq ft at 3 inches deep, and 81 sq ft at 4 inches deep. For most garden beds, 3 inches is the standard recommendation, so budget on 108 sq ft per cubic yard.
Summary: The Key Numbers to Remember
| Key Conversion | Value |
|---|---|
| 1 cubic yard | 27 cubic feet |
| 1 cubic yard | 46,656 cubic inches |
| 1 cubic yard at 1″ deep | covers 324 sq ft |
| 1 cubic yard at 2″ deep | covers 162 sq ft |
| 1 cubic yard at 3″ deep | covers 108 sq ft |
| 1 cubic yard at 4″ deep | covers 81 sq ft |
| 1 cubic yard at 6″ deep | covers 54 sq ft |
| Shortcut formula | (sq ft × depth in inches) ÷ 324 |
Use our square feet to cubic yards calculator at the top of this page for any combination of dimensions, depth, and material type — it handles the math instantly and outputs your result in cubic yards, cubic feet, and cubic metres so you can order in whatever unit your supplier uses.