How Much Mulch for 400 Square Feet?

Answer at a glance — 400 sq ft

Depth	Cu ft	Cu yards	2 cu ft bags (with 5% waste)
1 inch	33.3	1.23	18 bags
2 inches	66.7	2.47	36 bags
3 inches	100	3.7	53 bags
4 inches	133.3	4.94	71 bags
6 inches	200	7.41	105 bags

How we calculated it

For 400 sq ft at 3 inches:

1. Volume = 400 × 3 ÷ 12 = 100 cu ft
2. Cubic yards = 100 ÷ 27 = 3.7 cu yd
3. Bags (2 cu ft) = 3.7 × 13.5 = 50 → with 5% waste = 53 bags

Compare nearby sizes

Area	At 2"	At 3"	At 4"
200 sq ft	18 bags	27 bags	36 bags
300 sq ft	27 bags	40 bags	53 bags
400 sq ft	36 bags	53 bags	71 bags
600 sq ft	53 bags	79 bags	105 bags
800 sq ft	71 bags	105 bags	141 bags

Depth guide

• 1–2 inches — top-dressing existing mulch, lightweight coverage
• 3 inches — standard for flower beds, best weed suppression
• 4 inches — new beds or heavy clay soil where drainage is poor
• 6 inches — play areas, paths (not recommended for planted beds)

Bags vs. bulk

For 400 sq ft you need 3.7 cubic yards. If your local supplier charges less per yard in bulk than bags (≈13.5 bags per yard), bulk delivery saves money at this quantity.

Use the Mulch Calculator to enter your exact dimensions and get a precise bag count with an optional price estimate.