Cubic Feet, Cubic Yards, Square Feet: The Mulch Conversion Reference

The four conversion lines worth memorizing

1 cubic yard equals 27 cubic feet. This is the universal conversion every U.S. mulch buyer should know — supplier yards, bag-to-bulk math, and delivery sizing all run through this number.

1 cubic foot equals 7.48 gallons or 28.3 liters. Useful for converting between bagged mulch and liquid measurements you might already know (a 5-gallon bucket holds about 0.67 cu ft).

1 cubic meter equals 1.31 cubic yards or 35.3 cubic feet or 1,000 liters. The metric-imperial bridge for European and Asian buyers.

100 square feet at 3-inch depth equals 25 cubic feet equals 0.93 cubic yards. The standard mid-sized flower bed anchor that lets you scale everything else.

The cubic yards reference table

Order quantities at the standard 3-inch depth, with bag counts rounded up:

0.25 cu yd — 6.75 cu ft — 4 bags of 2 cu ft — 27 sq ft of coverage

0.5 cu yd — 13.5 cu ft — 7 bags of 2 cu ft — 54 sq ft

0.75 cu yd — 20.25 cu ft — 11 bags of 2 cu ft — 81 sq ft

1 cu yd — 27 cu ft — 14 bags of 2 cu ft — 108 sq ft

2 cu yd — 54 cu ft — 27 bags — 216 sq ft

3 cu yd — 81 cu ft — 41 bags — 324 sq ft (typical free-delivery threshold)

5 cu yd — 135 cu ft — 68 bags — 540 sq ft

10 cu yd — 270 cu ft — 135 bags — 1,080 sq ft

Square feet to depth, fast

If you know square footage and want cubic yards, multiply by depth (in inches) and divide by 324. So 200 sq ft at 3-inch depth = 200 × 3 ÷ 324 = 1.85 cu yd. At 4-inch depth: 200 × 4 ÷ 324 = 2.47 cu yd. The 324 in the denominator is the same 324 the coverage chart uses — it is just the cubic-feet-to-square-feet conversion at 1-inch depth.

For a metric version: cubic meters equals square meters times depth in centimeters divided by 100. So 20 m² at 7 cm depth = 20 × 7 ÷ 100 = 1.4 m³. Clean math; no division needed beyond 100.

The metric crossover table

For buyers in Europe, Asia, Latin America, and Canada (which uses metric for landscape supplies), the cubic meter and liter equivalents are:

1 m³ — 1,000 liters — 1.31 cubic yards — 35.3 cubic feet — covers 14 m² at 7 cm depth or 10 m² at 10 cm depth

1 liter — 0.001 m³ — 0.035 cu ft — about 60 cm² at 7 cm depth (negligible alone, useful for bag-to-volume math)

50-liter bag — 0.05 m³ — 1.77 cu ft — covers about 0.7 m² at 7 cm depth (most common European bag size)

70-liter bag — 0.07 m³ — 2.47 cu ft — covers about 1 m² at 7 cm depth (larger European size, slightly more than a U.S. 2 cu ft bag)

80-liter bag — 0.08 m³ — 2.83 cu ft — covers about 1.14 m² at 7 cm depth

Three unit traps that cost real money

First trap: 27 vs 27 confusion. 27 cubic feet equals 1 cubic yard. 27 bags of 2 cu ft does NOT equal 1 cubic yard — that is 54 cu ft, or 2 cubic yards. Read the unit you are multiplying carefully.

Second trap: 100 sq ft is not 100 cu ft. Area and volume are different. A 100 sq ft bed at 3-inch depth equals 25 cubic feet of mulch, not 100. Multiply by depth in feet (3 inches = 0.25 ft) to convert area to volume.

Third trap: ordering by weight when supplier sells by volume. Most mulch yards quote in cubic yards or cubic meters. A few quote in tons or kilograms. If your supplier weighs the order, ask for the volume equivalent before agreeing to a price — 1 cubic yard of dry hardwood mulch weighs about 800 to 1,000 lbs (360 to 450 kg), but a wet load can run 30 percent heavier without delivering more volume.

Printable quick-reference card

If you mulch once or twice a year, these are the only conversions you actually need:

1 cubic yard = 27 cubic feet = 13.5 bags of 2 cu ft = covers 108 sq ft at 3-inch depth

1 cubic meter = 1.31 cubic yards = 14 bags of 70 liters = covers 14 m² at 7 cm depth

100 sq ft of bed at 3 inches = 1 cubic yard (with buffer) = 13-14 bags

10 m² of bed at 7 cm = 0.7 cubic meters = 10 bags of 70 L (with buffer)