Short answer: At the standard depth of 3 inches, one cubic yard of mulch covers about 108 square feet. That's the same as about 13 to 14 bags of the common 2-cubic-foot size.
So a 100 sq ft flower bed needs just under 1 cubic yard (about 13 bags), and a 300 sq ft bed needs nearly 3 cubic yards (about 38 bags).
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Calculate bags or cubic yards of mulch for your landscaping.
The Simple Mulch Formula
Mulch is measured by volume, so you need three numbers: length, width, and depth.
- Find the area: length × width (in feet). A 10 × 20 ft bed is 200 sq ft.
- Convert depth to feet: 3 inches ÷ 12 = 0.25 ft.
- Multiply: 200 × 0.25 = 50 cubic feet.
- Convert to what you're buying:
- Bags: 50 ÷ 2 cu ft per bag = 25 bags
- Bulk: 50 ÷ 27 cu ft per yard = 1.85 cubic yards
For round or irregular beds, estimate the area as a rectangle and subtract a little, or use πr² for circles (a 6 ft wide circle around a tree is about 28 sq ft).
How Much Mulch Chart
All numbers below use the same math as our mulch calculator. Bag counts assume standard 2-cubic-foot bags.
| Bed area | 2" deep | 3" deep | 4" deep |
|---|---|---|---|
| 50 sq ft | 0.31 yd (5 bags) | 0.46 yd (7 bags) | 0.62 yd (9 bags) |
| 100 sq ft | 0.62 yd (9 bags) | 0.93 yd (13 bags) | 1.23 yd (17 bags) |
| 200 sq ft | 1.23 yd (17 bags) | 1.85 yd (25 bags) | 2.47 yd (34 bags) |
| 300 sq ft | 1.85 yd (25 bags) | 2.78 yd (38 bags) | 3.70 yd (50 bags) |
| 500 sq ft | 3.09 yd (42 bags) | 4.63 yd (63 bags) | 6.17 yd (84 bags) |
| 1,000 sq ft | 6.17 yd (84 bags) | 9.26 yd (125 bags) | 12.35 yd (167 bags) |
Buying 3-cubic-foot bags instead? Divide the cubic feet by 3. A 200 sq ft bed at 3 inches needs 17 of those.
How Deep Should Mulch Be?
- 2 inches: a light top-up on beds that already have a layer from last year
- 3 inches: the sweet spot for new beds. Deep enough to block weeds and hold moisture
- 4 inches: only for heavy weed pressure or paths. Deeper than this can starve roots of air
Never pile mulch against tree trunks or plant stems ("volcano mulching"). Keep it 3 to 6 inches away from trunks. Mulch pressed against bark holds moisture and invites rot, insects, and rodents.
Bagged vs. Bulk: Which Is Cheaper?
Bagged mulch costs more per cubic foot but needs no delivery and stores neatly. Bulk mulch is cheaper per yard but usually comes with a delivery fee and a pile in your driveway.
Using typical prices (about $4.50 per 2 cu ft bag, about $30 per cubic yard of hardwood bulk mulch before delivery):
| Project size | Bagged cost | Bulk cost (before delivery) |
|---|---|---|
| 100 sq ft at 3" | ~$59 (13 bags) | ~$28 |
| 300 sq ft at 3" | ~$171 (38 bags) | ~$83 |
| 500 sq ft at 3" | ~$284 (63 bags) | ~$139 |
Rule of thumb: below about 2 cubic yards, bags are usually simpler once you add a delivery fee. Above 2 to 3 yards, bulk almost always wins. Prices vary a lot by region, so get a local quote before you decide.
Which Type of Mulch Should You Use?
- Shredded hardwood: the all-rounder. Knits together, stays put on slopes, breaks down into good soil.
- Pine bark nuggets: lighter and long-lasting, but can float away in heavy rain.
- Rubber mulch: lasts for years and is popular for playgrounds, but doesn't improve your soil.
- Stone or gravel: permanent and fire-resistant, but heavy (about 2,700 lb per yard) and it heats up in summer sun.
Tools That Make Mulching Easier
True Temper
Steel Wheelbarrow, 6 Cubic Foot
- ✓Moves 3 bags per trip
- ✓Steel tray for heavy loads
- ✓Pneumatic tire
Fiskars
Bow Rake for Spreading Mulch
- ✓Spreads mulch evenly
- ✓Sturdy steel tines
- ✓Long handle saves your back
Radius Garden
Landscape Edging Spade
- ✓Crisp bed edges
- ✓Keeps mulch off the lawn
- ✓Cuts through sod
Wells Lamont
Heavy-Duty Garden Gloves
- ✓Protects from splinters
- ✓Reinforced palms
- ✓Breathable back
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The Bottom Line
- 1 cubic yard covers about 108 sq ft at 3 inches
- 1 cubic yard = 13.5 bags of 2 cu ft mulch
- Spread 2–3 inches deep and keep it off trunks and stems
- Buy bulk once you need more than 2–3 yards
Measure your beds and plug them into the free mulch calculator to get cubic feet, yards, bag counts, and a cost estimate for both options.
