Mulch Calculator
How much mulch do you need? Enter your bed size, mulch depth, and the bag size on the label to get cubic yards and a whole-bag count.
- Free, no signup
- Formula shown
- Rounds up to whole units
- Updated October 2026
Mulch needed · 5% allowance
1.94cubic yards
Bags to buy
27 bags
2 cu ft each
Bulk order
2 yd³
¼ cubic yard steps
- Before allowance
- 1.85 yd³
- Cubic feet
- 52.5 ft³
- Cubic meters
- 1.49 m³
Bag sizes vary by brand. Enter the volume printed on the bag you are buying.
AnswerA 20 ft × 10 ft bed mulched 3 in deep needs 1.85 cubic yards of mulch (1.94 with a 5% allowance): buy 27 2 cu ft bags or 2 cubic yards in bulk.
How to use this mulch calculator
- Measure the bed's length and width. For several beds, run each one and add the results.
- Enter the depth you plan to spread. The default is an example only. The right depth depends on the mulch type, the plants, and what is already in the bed.
- Set an allowance for settling, uneven ground, or topping up edges.
- Enter the bag volume printed on the bag you're buying, in cubic feet or liters. Bags differ between brands and stores.
- If buying bulk, choose the increment your supplier sells in.
How to calculate mulch: the formula, shown
Mulch volume is bed area × depth. Convert depth to feet (inches ÷ 12), multiply by the area in square feet to get cubic feet, and divide by 27 for cubic yards. For bags, divide cubic feet by the volume printed on the bag and round up to a whole bag.
Default example. A 20 ft × 10 ft bed at 3 in, a 5% allowance, and 2 cu ft bags. The 3 in depth is only an example input, not a planting recommendation. The 2 cu ft size is the one listed for Scotts Nature Scapes mulch. Change the inputs above and the result panel recalculates; this worked example always shows the default.
Area = 20 ft × 10 ft = 200 ft² Depth = 3 in ÷ 12 = 0.25 ft Volume = 200 ft² × 0.25 ft = 50 ft³ = 1.8519 yd³ Allowance = 50 ft³ × (1 + 5/100) = 52.5 ft³ = 1.9444 yd³ Bags = 52.5 ft³ ÷ 2 ft³/bag = 26.25 → 27 bags Bulk order = 1.9444 ÷ 0.25 = 7.778 → 8 steps = 2 yd³ Metric = 52.5 ft³ × 0.3048³ = 1.4866 m³
A shortcut: one cubic yard spread 3 in deep covers 324 ÷ 3 = 108 square feet, because 27 ft³ × 12 in/ft = 324 square-foot-inches.
How much mulch do I need for common bed sizes?
Mulch for common bed areas at 2, 3, and 4 inches deep: cubic yards, and the number of 2 cu ft bags (the size Scotts lists for its Nature Scapes mulch). Computed with the same formula as the calculator, with no allowance. Bags are rounded up to whole bags.
| Bed area | 2 in: yd³ / bags | 3 in: yd³ / bags | 4 in: yd³ / bags |
|---|---|---|---|
| 50 sq ft | 0.31 yd³ / 5 | 0.46 yd³ / 7 | 0.62 yd³ / 9 |
| 100 sq ft | 0.62 yd³ / 9 | 0.93 yd³ / 13 | 1.23 yd³ / 17 |
| 200 sq ft | 1.23 yd³ / 17 | 1.85 yd³ / 25 | 2.47 yd³ / 34 |
| 300 sq ft | 1.85 yd³ / 25 | 2.78 yd³ / 38 | 3.7 yd³ / 50 |
| 500 sq ft | 3.09 yd³ / 42 | 4.63 yd³ / 63 | 6.17 yd³ / 84 |
| 1000 sq ft | 6.17 yd³ / 84 | 9.26 yd³ / 125 | 12.3 yd³ / 167 |
If your bags are a different size, enter it in the calculator. The bag count changes with the bag volume.
How much mulch to buy: bags or bulk
For the default bed, buy 27 bags of 2 cu ft, or 2 yd³ in bulk (1.94 yd³ needed).
- Bags: buy whole bags for the size on the label. If you change brands, re-enter the bag volume, because the bag count changes with it.
- Bulk: suppliers usually sell by the cubic yard or cubic meter. Ask about minimum loads and delivery. See planning a delivery.
- Which is better: compare cost per cubic yard for both options using your local prices. The bagged vs bulk guide shows how.
Bark, wood chips, and pine straw
Shredded bark, wood chips, and dyed mulch all use the same volume calculation: area × depth. Enter the bag volume printed on the product you buy, because bag sizes differ between brands and stores.
Pine straw calculator
Pine straw is commonly sold in bales rather than by volume, so a cubic-yard figure does not tell you how many bales to buy. Measure the bed area here (length × width), ask your supplier how many square feet one bale covers at the depth you want, and divide the area by that figure. Round up to whole bales.
Tips for measuring mulch beds
- Check depth with a ruler in a few spots as you spread. It's easy to put down more than planned near the bag or pile.
- For round or curved beds, use the methods in measuring irregular areas.
- If some old mulch is still in place, measure it and subtract it from the depth you're aiming for.
- Bags labeled in liters can be entered directly. The calculator converts them (1 cu ft = 28.317 L).
Mulch calculator FAQ
How much mulch do I need?
Multiply the bed's length × width in feet by the depth in feet (inches ÷ 12) to get cubic feet. Divide by 27 for cubic yards, or divide cubic feet by the bag volume on the label for a bag count. Round bags up to a whole bag.
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so divide 27 by the bag volume on your label. With 2 cu ft bags that is 13.5, so 14 whole bags. With 3 cu ft bags it is exactly 9.
How much mulch for a 10 x 20 bed 3 inches deep?
50 cubic feet, or 1.85 cubic yards, before any allowance. With a 5% allowance that is 52.5 cubic feet: 27 bags of 2 cu ft, or 2 cubic yards in quarter-yard steps.
How many square feet does a cubic yard of mulch cover?
Divide 324 by the depth in inches. At 2 inches one cubic yard covers 162 square feet, at 3 inches 108 square feet, and at 4 inches 81 square feet.
How deep should mulch be?
This calculator does not recommend a depth. The right depth depends on the material, the plants, and local conditions. Check guidance from your local extension service or the mulch manufacturer, then enter that depth.
Are all mulch bags the same size?
No. Bag volume varies by brand and product. For example, Scotts lists its Nature Scapes Color Enhanced Mulch in both 2 cu ft and 1.5 cu ft sizes. Enter the volume printed on your bag.
My mulch bag is labeled in liters. Can I use it?
Yes. Switch the bag unit to liters and enter the label volume. The calculator converts using 1 cubic foot = 28.316846592 liters.
Does this calculator work for pine straw?
Not directly. Pine straw is commonly sold in bales rather than by volume, so a cubic-yard figure does not tell you how many bales to buy. Ask your supplier how many square feet one bale covers at your depth, then divide the bed area by that figure.
Related calculators and guides
Calculators
- Topsoil Calculator — Topsoil volume in cubic yards and meters for lawns, beds, and fill, with an optional weight from your supplier's density.
- Gravel Calculator — Gravel, crushed rock, or landscape rock volume in cubic yards and meters, with an optional weight from your supplier's density.
- Concrete Calculator — Slab volume in cubic feet, cubic yards, and cubic meters, with ready-mix order size and bag counts for documented products.
Guides
- Bagged vs. Bulk Materials: Which Should You Buy? — How to compare bags and bulk delivery using bags per cubic yard and your own local prices.
- What Is a Cubic Yard? — What a cubic yard is, how to convert area × depth into yards, and how much ground one yard covers.
- How to Measure an Irregular Area — Split odd shapes into rectangles, triangles, circles, and trapezoids, then average width and depth.
- How to Plan a Bulk Material Delivery — Rounding to supplier increments, questions to ask, and a checklist before bulk material arrives.
Sources
- Scotts Nature Scapes Color Enhanced Mulch product page — The Scotts Company. Used for: 2 cu ft per bag (a 1.5 cu ft size is also listed). Checked 2026-10-03.
- NIST Guide to the SI, Appendix B.9: Factors for units listed by kind of quantity — National Institute of Standards and Technology. Used for: 1 ft = 0.3048 m (exact); 1 in = 2.54 cm (exact). Checked 2026-10-03.
- NIST Handbook 44 (2026), Appendix C: General Tables of Units of Measurement — National Institute of Standards and Technology. Used for: 1 yd³ = 27 ft³; 1 US gal = 231 in³. Checked 2026-10-03.