How Many Bags of Mulch Do I Need?
By Vinod Kondeti · Updated
If you already know the area, this is the quickest way to a shopping list. Scotts' own table says a 1.5 cu ft bag covers 6 ft² at 3 inches. That matches the math (1.5 × 12 ÷ 3 = 6), and this calculator uses the same rule for any bag size.
How do I measure for a mulch bags project?
- Change the bag size to whatever is printed on the bag you are buying.
- Round up to whole bags. The calculator does this for you.
- Fine shredded mulches may be sold for a thinner layer. Scotts rates its Triple Shred at 2 inches.
How is the mulch bags amount calculated?
- Cubic feet = length × width × (depth in inches ÷ 12)
- Cubic yards = ft³ ÷ 27
- Bags = ft³ ÷ bag size (ft³), rounded up
- One bag covers (bag ft³ × 12) ÷ depth (in) square feet; 1 yd³ covers 324 ÷ depth (in) ft²
- Extra for waste/settling: volume × (1 + % ÷ 100)
- Round bed: π × (d ÷ 2)²; tree ring: π ÷ 4 × (outer² − inner²)
- Bulk cost = yd³ × $/yd³ + delivery; bag cost = bags × $/bag
Mulch bags calculator questions
How many 2 cu ft bags for 100 ft² at 3 inches?
25 ft³ ÷ 2 = 12.5, so 13 bags before extra (14 with the 10% default).
How many 1.5 cu ft bags for the same area?
25 ÷ 1.5 = 16.7, so 17 bags before extra.
Sources
Estimates only. Use the coverage or bag size printed on your product. Read the mulch guide for worked examples.
More mulch calculators
- Mulch calculator (main)
- Cubic yards calculator
- Depth & coverage calculator
- Tree ring calculator
- Round bed calculator
- Multiple beds calculator
- Gravel calculator
- Topsoil calculator