How to use the mulch calculator calculator
- 1
Pick a shape
Choose the shape that matches your bed: rectangle, square, circle, triangle, trapezoid, a border, or a known area. Add a section for each separate bed.
- 2
Enter the measurements
Type the dimensions in the unit you select. For a known area, enter the square footage directly.
- 3
Set the mulch depth
Enter how deep you want the mulch and choose the depth unit. Most landscaping mulch is entered in inches.
- 4
Add options if needed
Add a waste allowance, a bag volume to see bags, and your own bulk or bag prices to estimate cost.
- 5
Review the result
Read the cubic yards, cubic feet, bag count, and cost. Compare your entered pricing and purchasing options before ordering.
Formula
Cubic yards = square feet x depth (in) / 324
The number 324 is 27 cubic feet per cubic yard times 12 inches per foot. Multiply each section's area by the depth, add the sections, then divide by 324. For bags, divide the cubic feet needed by the bag volume and round up.
Worked example
A rectangular flower bed measures 20 feet by 8 feet and will be mulched 3 inches deep.
- 1Find the area: 20 x 8 = 160 square feet.
- 2Apply the formula: 160 x 3 / 324 = 1.48 cubic yards.
- 3In cubic feet that is 160 x (3 / 12) = 40 cubic feet.
- 4With 2 cubic foot bags: 40 / 2 = 20 bags.
The bed needs about 1.48 cubic yards, or roughly 40 cubic feet of mulch.
Worked examples
Circular tree ring
A ring of 6 foot diameter, mulched 3 inches deep.
- 1Circle area = 3.14159 x (6 / 2)^2 = 28.27 square feet.
- 228.27 x 3 / 324 = 0.26 cubic yards.
- 3In cubic feet: 28.27 x 0.25 = 7.07 cubic feet.
About 0.26 cubic yards, or roughly 7.1 cubic feet.
Two separate beds
A 12 by 4 foot bed and a 10 by 5 foot bed, both 2 inches deep.
- 1Bed one: 12 x 4 = 48 square feet.
- 2Bed two: 10 x 5 = 50 square feet.
- 3Total area = 98 square feet.
- 498 x 2 / 324 = 0.60 cubic yards.
The two beds together need about 0.60 cubic yards.
Mulch border around a patio
A 2 foot wide border around a 16 by 12 foot patio, 3 inches deep.
- 1Outer area = 20 x 16 = 320 square feet (patio plus border on all sides).
- 2Inner area = 16 x 12 = 192 square feet.
- 3Border area = 320 - 192 = 128 square feet.
- 4128 x 3 / 324 = 1.19 cubic yards.
The border alone needs about 1.19 cubic yards.
Bag-based estimate
A 300 square foot bed at 2 inches deep, using 2 cubic foot bags.
- 1Cubic feet = 300 x (2 / 12) = 50 cubic feet.
- 2Bags = 50 / 2 = 25 bags exactly.
- 3Round up only if the result is not a whole number.
The bed needs 50 cubic feet, which is 25 of the 2 cubic foot bags.
How mulch volume is calculated
Mulch is sold by volume, so a length and width alone are not enough. You also need a depth, because volume is area multiplied by thickness. The calculator finds the area of each shape you enter, multiplies by the depth, and adds the sections together.
Once you have a volume in cubic feet, dividing by 27 gives cubic yards, the unit most bulk suppliers use. If you prefer to work from square feet and inches directly, multiply the area by the depth in inches and divide by 324. Both routes give the same answer because 27 times 12 is 324.
How much area one cubic yard covers
A single cubic yard of mulch spreads further when it is thinner and covers less ground when it is deeper. At 1 inch deep, one cubic yard covers 324 square feet. At 3 inches it covers 108 square feet, and at 6 inches it covers 54 square feet.
The coverage table below lists common depths so you can sanity check a bulk order. To work coverage out for any volume, the cubic yards to square feet calculator does it in one step.
Using multiple landscape sections
Most yards are not one tidy rectangle. To handle several beds at once:
- 1Add a section for each separate bed or border.
- 2Pick the shape that best matches each one.
- 3Use the quantity field when several beds are identical.
- 4The calculator adds every section into one total volume and bag count.
Bulk mulch versus bags
Bulk mulch is delivered or picked up by the cubic yard, while bagged mulch is sold in bags labeled by cubic foot volume. The same project volume can be bought either way. Bags are easy to carry and store, while bulk can suit larger areas, but the right choice depends on your access, storage, and pricing.
Enter a bag volume to see the bag count, and add your own prices to compare totals. For a deeper comparison, see bulk mulch vs bagged mulch.
Waste allowance and measurement variation
Real beds are rarely perfect rectangles, and mulch settles, spills, and gets raked unevenly. A small waste allowance adds a margin so you do not run short. The calculator lets you set your own percentage rather than forcing one value.
Keep the unrounded number while planning and round up only when you place the order. Confirm the final amount with your supplier.
How to compare mulch cost
Cost depends entirely on the prices you are quoted, so the calculator never assumes a price. Enter a bulk price per cubic yard, or a bag volume with a price per bag, and add any delivery or fixed fees. When both are entered, the result shows each total and the arithmetic difference.
For a dedicated cost breakdown with separate bulk and bagged fees, use the mulch cost calculator.
Common mistakes
A few simple errors cause most wrong mulch estimates:
- Leaving out depth and treating square feet as if they were a volume
- Mixing units, such as entering width in feet but depth in a different system without converting
- Assuming every bag holds the same cubic feet instead of reading the label
- Forgetting to add separate beds together
- Rounding each measurement early instead of at the final order step
- Confusing cubic yards with tons, which would need a verified mulch density
How Much Area One Cubic Yard of Mulch Covers
Square feet that one cubic yard covers at each depth, from 324 divided by the depth in inches.
| Cubic yards | 1 in | 2 in | 3 in | 4 in | 5 in | 6 in | 8 in | 12 in |
|---|---|---|---|---|---|---|---|---|
| 1 | 324 sq ft | 162 sq ft | 108 sq ft | 81 sq ft | 64.8 sq ft | 54 sq ft | 40.5 sq ft | 27 sq ft |
Square Feet to Mulch Cubic Yards by Depth
Cubic yards needed for each area and depth. Read your area on the left and depth across the top. Every value is square feet times depth in inches divided by 324.
| Area | 1 in | 2 in | 3 in | 4 in | 6 in |
|---|---|---|---|---|---|
| 25 sq ft | 0.0772 | 0.154 | 0.231 | 0.309 | 0.463 |
| 50 sq ft | 0.154 | 0.309 | 0.463 | 0.617 | 0.926 |
| 100 sq ft | 0.309 | 0.617 | 0.926 | 1.23 | 1.85 |
| 150 sq ft | 0.463 | 0.926 | 1.39 | 1.85 | 2.78 |
| 200 sq ft | 0.617 | 1.23 | 1.85 | 2.47 | 3.7 |
| 300 sq ft | 0.926 | 1.85 | 2.78 | 3.7 | 5.56 |
| 500 sq ft | 1.54 | 3.09 | 4.63 | 6.17 | 9.26 |
| 750 sq ft | 2.31 | 4.63 | 6.94 | 9.26 | 13.89 |
| 1,000 sq ft | 3.09 | 6.17 | 9.26 | 12.35 | 18.52 |
Bags per Cubic Yard by Bag Volume
How many bags make one cubic yard, by the cubic feet printed on the bag. Verify the volume shown on your actual bag label, which can vary by product.
| Bag volume | Bags per cubic yard | Whole bags for 1 cubic yard |
|---|---|---|
| 0.75 cu ft | 36 | 36 |
| 1 cu ft | 27 | 27 |
| 1.5 cu ft | 18 | 18 |
| 2 cu ft | 13.5 | 14 |
| 3 cu ft | 9 | 9 |
Frequently asked questions
- How much mulch do I need?
- Measure the area of each bed, multiply by the mulch depth, and divide square feet times depth in inches by 324 to get cubic yards. The calculator does this for one or many sections and can also show the bag count.
- How many cubic feet are in a cubic yard of mulch?
- Exactly 27 cubic feet, because a cubic yard is a 3 foot by 3 foot by 3 foot cube. This is true for mulch and every other bulk material.
- How many bags of mulch make a cubic yard?
- Divide 27 by the cubic feet printed on the bag. For 2 cubic foot bags that is about 14 bags, and for 1.5 cubic foot bags it is 18 bags. Always check the volume on the actual bag.
- What depth of mulch should I use?
- It depends on the mulch type, the plants, and local guidance, so there is no single universal depth. Pick the finished thickness your project calls for and confirm it with your supplier or a local extension service. The calculator works for any depth you enter.
- How much area does a cubic yard of mulch cover?
- It depends on depth. One cubic yard covers 324 square feet at 1 inch, 108 square feet at 3 inches, and 54 square feet at 6 inches.
- Can I calculate mulch for an odd-shaped bed?
- Yes. Split the bed into rectangles, circles, or triangles, add a section for each, and the calculator combines them. You can also enter a known area directly.
- Should I add extra mulch for waste?
- A small waste allowance helps cover settling, spillage, and uneven beds. Set your own percentage, then round up at the ordering stage.
- Can I convert mulch cubic yards to tons?
- Not without a verified mulch density. Weight depends on the mulch type and moisture, so YardCalc does not convert mulch volume to tons unless a sourced density is selected.
Mulch volume uses the exact factors of 27 cubic feet per cubic yard and 324 square feet per cubic yard inch. Bag counts divide the required cubic feet by your entered bag volume and round up. Cost uses only prices you enter. Tables are generated by the shared calculation engine. See the YardCalc calculation methodology.
Results are planning estimates. Last reviewed 2026-06-25.