Bulk vs Bagged Mulch and Soil Cost Calculator

How it works

Bagged material is bought by the whole bag, so its cost is the volume in cubic feet divided by the bag size, rounded up, times the price per bag. Bulk material is priced per cubic yard (27 cu ft) plus a delivery fee, so its cost is the cubic yards times the price per yard plus the fee.

The delivery fee is a fixed cost that bulk has to earn back. Each cubic yard bought in bags costs the bag price × 27 ÷ bag size; each yard bought in bulk costs the bulk price. When bags cost more per yard, the difference pays off the delivery fee at the break-even volume: the fee divided by the difference in price per yard. Above that volume bulk is cheaper; below it, bags are, apart from the rounding to whole bags. When bags cost no more per yard than bulk there is no break-even: bulk has no per-yard saving to repay the fee, although on a small order the extra part bag can still make bulk the cheaper buy.

Formula

cu ft            = volume in cu ft;   cu yd = cu ft ÷ 27
bags             = ⌈ cu ft ÷ bag size ⌉, at least 1
bagged cost      = bags × price per bag
bulk cost        = cu yd × bulk price per cu yd + delivery fee
bagged $/cu yd   = price per bag × 27 ÷ bag size
break-even cu yd = delivery fee ÷ (bagged $/cu yd − bulk $/cu yd)   when bagged $/cu yd > bulk $/cu yd

Example

3 cu yd is 81 cu ft, or 81 ÷ 2 = 40.5 → 41 two-cubic-foot bags. At $4.50 a bag that is $184.50. In bulk at $38 a yard plus $65 delivery it is 3 × 38 + 65 = $179.00, so bulk is cheaper by $5.50.

Bags work out at 4.50 × 27 ÷ 2 = $60.75 per cubic yard, $22.75 more than bulk, so the $65 delivery fee is earned back at 65 ÷ 22.75 = 2.86 cu yd.

Assumptions and limitations

• All prices are inputs; the defaults are illustrative, not current market prices. Mulch, soil and compost prices vary widely by region, product and season.
• Bulk is priced on the exact volume. Many suppliers sell in half or whole yards and have a minimum order, which raises the bulk cost of a small job above the figure here.
• The break-even volume treats bags as divisible. The cost comparison uses whole bags, so on a small order the rounding up to a whole bag can make the cheaper option differ from what the break-even alone suggests.
• Sales tax, bag-quantity discounts, pallet pricing and the cost of your own time and vehicle for collecting bags are not included.
• Bag volumes are nominal and a bulk yard is measured loose at the yard; the two may not settle to quite the same volume once spread.

Frequently asked questions