Mulch Calculator
Work out exactly how much mulch to buy: enter your bed dimensions and depth to get cubic yards and bag counts, with an instant cost comparison between bulk and bagged.
2–3″ around plants, 3–4″ open beds
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Enter prices to compare bulk vs bags.
You might also need:Topsoil Calculator·Cubic Yard Calculator
How to calculate mulch
Mulch is sold by the cubic yard (bulk delivery) or by the bag. Measure your bed's length and width in feet, decide on a depth in inches, and convert:
bags needed = cubic feet ÷ bag size (2 or 3 cu ft)
A 12 × 4 ft bed at 3 inches deep needs 12 cubic feet — that's 6 standard bags, or just under half a cubic yard. For multiple beds, calculate each and add the totals.
Mulch coverage chart
| Amount | At 2″ deep | At 3″ deep | At 4″ deep |
|---|---|---|---|
| 1 bag (2 cu ft) | 12 sq ft | 8 sq ft | 6 sq ft |
| 1 bag (3 cu ft) | 18 sq ft | 12 sq ft | 9 sq ft |
| 1 cubic yard | 162 sq ft | 108 sq ft | 81 sq ft |
| 5 cubic yards | 810 sq ft | 540 sq ft | 405 sq ft |
Choosing a mulch type
- Shredded hardwood: the all-rounder — knits together on slopes, cheap, feeds soil as it breaks down.
- Cedar & cypress: slower to decompose and naturally insect-resistant, but pricier.
- Dyed mulch (black/brown/red): holds color for a season or two; buy from a reputable yard to avoid dyed construction waste.
- Pine straw: light, cheap and great under acid-loving shrubs; needs topping up more often.
- Rubber mulch: lasts a decade under playgrounds, but adds nothing to the soil — avoid it in planting beds. For stone alternatives see our river rock calculator.
Frequently asked questions
How many bags of mulch are in a cubic yard?+
One cubic yard equals 13.5 bags of 2-cubic-foot mulch, or 9 bags of 3-cubic-foot mulch. If you need more than about 10 bags, bulk delivery by the yard is usually cheaper.
How deep should mulch be?+
Spread mulch 2–3 inches deep around plants and 3–4 inches on open beds and around trees. Anything over 4 inches can suffocate roots and hold too much moisture against stems. Keep mulch 2–3 inches away from trunks.
How much does a yard of mulch cover?+
One cubic yard covers about 108 square feet at 3 inches deep, or 162 square feet at 2 inches. A typical 2-cubic-foot bag covers 8 square feet at 3 inches.
How much does mulch cost?+
Bulk hardwood mulch typically costs $30–$60 per cubic yard plus delivery, while bagged mulch runs $3–$7 per 2-cubic-foot bag — about $40–$95 per yard equivalent. Dyed and premium mulches (cedar, cypress, rubber) cost more.
When is the best time to mulch?+
Mid-to-late spring, after soil has warmed, is ideal for most gardens — it locks in moisture ahead of summer. A lighter fall top-up insulates roots for winter. Plan on refreshing organic mulch once a year as it decomposes.