How Much Mulch for 100 Square Feet? (Bags & Cubic Yards)

For 100 square feet at 3 inches deep — the most common mulch depth — you need just under 1 cubic yard, which is 13 to 14 bags of 2 cu ft mulch.

The answer at a glance — 100 sq ft

Depth	Cu ft	Cu yards	2 cu ft bags (w/ 5% waste)
1 inch	8.3	0.31	5 bags
2 inches	16.7	0.62	10 bags
3 inches	25.0	0.93	14 bags
4 inches	33.3	1.23	18 bags
6 inches	50.0	1.85	27 bags

How we calculated it

For 100 sq ft at 3 inches:

Volume = 100 × 3 ÷ 12 = 25 cu ft
Cu yd = 25 ÷ 27 = 0.926 cu yd
Bags = 0.926 × 13.5 = 12.5 → 13 bags (without waste)
With 5% waste: 12.5 × 1.05 = 13.1 → 14 bags

For other area sizes

Area	At 2” depth	At 3” depth	At 4” depth
50 sq ft	5 bags	7 bags	9 bags
100 sq ft	10 bags	14 bags	18 bags
200 sq ft	19 bags	27 bags	36 bags
300 sq ft	28 bags	40 bags	54 bags
500 sq ft	46 bags	67 bags	90 bags

All bag counts include 5% waste, rounded up.

When to buy bulk vs. bags

For 100 sq ft at 3 inches (14 bags), buying bags is convenient. At 13.5 bags per cubic yard, you need just under 1 full yard — buying bags from a garden center is easier than ordering a partial yard of bulk mulch. If you have multiple beds totaling 200+ sq ft, compare bulk delivery prices.

Use the Mulch Calculator for your exact bed dimensions and depth.

Frequently Asked Questions

How many bags of mulch for 100 square feet at 3 inches?

For 100 sq ft at 3 inches deep, you need 0.93 cubic yards of mulch, which equals 13 bags (2 cu ft each) before waste. With a 5% waste factor, round up to 14 bags.

How many cubic yards of mulch for 100 square feet?

100 sq ft at 3 inches deep = 100 × 3 ÷ 324 = 0.93 cubic yards. At 2 inches: 0.62 cu yd. At 4 inches: 1.23 cu yd.

How much mulch do I need for 100 sq ft at 2 inches?

At 2 inches deep, 100 sq ft needs 0.62 cubic yards (17 cu ft), which equals 9 bags of 2 cu ft mulch. Add 5% waste for 10 bags.

Is 1 cubic yard of mulch enough for 100 square feet?

Yes — 1 cubic yard covers 108 sq ft at 3 inches deep, 162 sq ft at 2 inches, or 81 sq ft at 4 inches. For 100 sq ft at 3 inches, you need slightly less than 1 cubic yard.