How Many Square Feet and Cubic Feet Are in a Yard?

A square yard equals 9 square feet (3 ft × 3 ft). A cubic yard equals 27 cubic feet (3 ft × 3 ft × 3 ft).

These two numbers show up constantly in landscaping and construction. Suppliers sell mulch, topsoil, gravel, and concrete “by the yard.” That means a cubic yard — a unit of volume, not area.

Square feet to square yards

square yards = square feet ÷ 9

Divide square feet by 9 to get square yards. A 900 sq ft lawn works out to 100 square yards (900 ÷ 9). Sod and carpet pricing both use this conversion, since both are quoted per square yard.

The same math covers a concrete patio’s surface area. A 12 ft × 15 ft slab measures 180 square feet, or 20 square yards (180 ÷ 9). But ordering the actual concrete needs cubic feet and cubic yards instead — concrete is sold by volume, not surface area.

Cubic feet to cubic yards (the landscaping conversion)

cubic yards = cubic feet ÷ 27

This conversion matters most when you’re ordering mulch, topsoil, gravel, or concrete. Suppliers sell “by the yard,” and one cubic yard always equals 27 cubic feet of volume.

That relationship never changes, no matter the material. It comes from the yard’s fixed 3-foot length, not from anything about what fills it.

Worked example: how much mulch do I need?

Say you’re covering a 200 sq ft garden bed with 3 inches (0.25 ft) of mulch.

1. Volume needed = 200 sq ft × 0.25 ft = 50 cubic feet
2. Cubic yards = 50 ÷ 27 = 1.85 cubic yards

Round up to 2 yards when you order, since suppliers sell in whole or half-yard increments. As a rule of thumb, one cubic yard of mulch spread 3 inches deep covers about 108 square feet (27 ÷ 0.25).

Spread it thinner, at 2 inches, and that same cubic yard stretches to cover about 162 square feet. Less material goes down per square foot of ground.

Worked example: concrete for a slab

A 10 ft × 10 ft slab (100 sq ft) poured 4 inches thick needs this:

1. Volume = 10 × 10 × 0.33 = 33 cubic feet
2. Cubic yards = 33 ÷ 27 = 1.22 cubic yards

Ready-mix suppliers round up to the nearest quarter or half yard. Most also charge a minimum-load fee. A small job like this one often gets billed as “1.5 yards,” even though the math says 1.22.

A thicker 6-inch (0.5 ft) driveway slab over that same 100 square feet needs 50 cubic feet, or 1.85 cubic yards. That’s nearly 50% more concrete for a 50% thicker pour — volume scales directly with depth.

Worked example: topsoil or dirt for a raised bed

A raised garden bed measuring 4 ft × 8 ft, filled 1 ft deep, needs:

1. Volume = 4 × 8 × 1 = 32 cubic feet
2. Cubic yards = 32 ÷ 27 = 1.19 cubic yards of topsoil

Bagged topsoil usually comes in 0.75 or 1.5 cubic-foot bags. This bed would need roughly 43 of the smaller bags (32 ÷ 0.75). That’s why buying loose topsoil “by the yard” almost always beats buying bags. The savings show up once a project passes a couple of cubic yards.

Quick reference table

Job	Coverage	Depth	Cubic feet	Cubic yards
Mulch, small bed	100 sq ft	3 in	25 cu ft	0.93 yd
Mulch, medium bed	200 sq ft	3 in	50 cu ft	1.85 yd
Topsoil, raised bed	32 sq ft	12 in	32 cu ft	1.19 yd
Gravel path	150 sq ft	4 in	50 cu ft	1.85 yd
Concrete slab	100 sq ft	4 in	33 cu ft	1.22 yd
Concrete driveway	100 sq ft	6 in	50 cu ft	1.85 yd

Why the number 27 specifically

A yard measures 3 feet. Cubic measurement cubes that number: 3 × 3 × 3 = 27 cubic feet per cubic yard. Squaring 3 gives you the 9 square feet per square yard the same way — cubic yards just add a third dimension.

That’s also why the conversion stays identical for mulch, dirt, gravel, or concrete. The 27-cubic-feet figure belongs to the yard as a unit of length, not to the material filling it. What changes between materials is weight per cubic yard, not volume.

Frequently Asked Questions

How many cubic feet are in a yard of mulch?
27 cubic feet. “A yard” of any bulk material — mulch, dirt, gravel, or concrete — always means one cubic yard, and one cubic yard is always 27 cubic feet.

How many cubic feet are in a yard of dirt?
Also 27 cubic feet. This conversion never changes based on material. Dirt, topsoil, mulch, sand, and gravel all convert the same way: 27 cubic feet to 1 cubic yard.

How many square feet are in a yard of concrete?
It depends on the slab’s thickness, since concrete is sold by volume, not area. One cubic yard poured 4 inches thick covers about 81 square feet (27 ÷ 0.33). At 6 inches thick, that same cubic yard covers only about 54 square feet.

How many square feet are in a yard of mulch?
Same logic as concrete — it depends on depth. One cubic yard spread at 3 inches covers about 108 square feet. At 2 inches, it covers about 162 square feet.

What is cubic feet per yard, exactly?
It’s the fixed conversion factor: 27 cubic feet make one cubic yard, always. “Cubic feet per yard” and “cubic feet in a cubic yard” mean the same thing. Both equal 27, whether you’re measuring mulch, dirt, gravel, sand, or poured concrete.

Why do landscaping suppliers sell by the cubic yard instead of cubic feet?
Cubic yards give bulk deliveries a more practical unit size. Ordering “2 yards of mulch” reads cleaner than “54 cubic feet of mulch,” even though the two describe the exact same amount of material.

How many cubic feet are in a yard of gravel?
Still 27 cubic feet, same as every other bulk material. A gravel path 150 sq ft wide and 4 inches deep needs 50 cubic feet, or about 1.85 cubic yards. Check the reference table above for more path and driveway sizes.

Do I need to round up when ordering by the yard?
Almost always, yes. Most suppliers deliver in half-yard or full-yard increments and won’t split a load into odd fractions. A project that calculates to 1.22 cubic yards typically gets ordered as 1.5 yards. Budget for that small overage instead of expecting the exact decimal.