Mulch calculator: how much mulch, soil or gravel you need
Measure the bed, pick a depth, and get the answer in cubic yards, bags and dollars. Works for mulch, topsoil, compost, pea gravel, river rock and decomposed granite.
Depth
160 sq ft of hardwood mulch (shredded) at 3 in deep
1.5 cubic yards
40 cu ft
Bagged
20 bags of 2 cu ft, or 14 bags of 3 cu ft.
$80 to $140
Bulk delivery
Order 2 yards (rounded up to whole yards, 1-yard minimum). Delivery fee not included.
$70 to $120
Rule of thumb
One cubic yard covers 108 sq ft at 3 in. Bulk beats bags above about 2 yards.
Prices are 2026 US retail ranges. Bulk is cheaper per yard but most yards charge $40 to $100 to deliver.
How the mulch math works
Mulch is sold by volume, and the volume you need is just area times depth. Measure the bed in feet, multiply length by width to get square feet, then multiply by the depth in inches and divide by 12. That gives cubic feet. Divide by 27 for cubic yards, which is the unit every bulk supplier quotes. A 20 by 8 foot bed at 3 inches is 160 square feet, 40 cubic feet, or 1.48 cubic yards.
The calculator does that for rectangles, circles (pi times the radius squared) and triangles (half the base times the height), or you can type in the total square footage if the bed is an odd shape. For an L-shaped or curved bed, split it into two or three rectangles, add them up, and use the total sq ft option. Being off by a few square feet does not matter. Being off by an inch of depth does, because depth is where most people under-order.
One cubic yard is a surprisingly useful number to memorize. It covers 324 square feet at 1 inch, 162 at 2 inches, 108 at 3 inches, and 81 at 4 inches. If you know your beds add up to about 300 square feet and you mulch at 3 inches, you need three yards, and you can sanity-check any quote against that.
| Depth | Sq ft covered per cubic yard | 2 cu ft bags per 100 sq ft |
|---|---|---|
| 1 inch | 324 | 5 |
| 2 inches | 162 | 9 |
| 3 inches | 108 | 13 |
| 4 inches | 81 | 17 |
| 6 inches | 54 | 25 |
How deep to go
For shredded hardwood or bark mulch on a perennial or shrub bed, 3 inches is the standard and 2 inches is enough for a refresh over last year's layer. Go to 4 inches around trees and in beds you want to keep weed-free with minimal effort, but keep it pulled back a few inches from trunks and plant crowns. Piling mulch against a trunk (the "mulch volcano") rots bark and invites borers. Six inches is only for wood chips on a path or a play area.
Stone is different. Pea gravel and decomposed granite go down at 2 to 3 inches over landscape fabric or compacted base, and 1.5-inch river rock needs about 2 inches to hide the ground beneath. Deeper stone just wastes money and is harder to walk on. Topsoil and compost depend on the job: 1 to 2 inches of compost as an amendment you'll dig in, 2 to 4 inches of topsoil to level or build up a bed, 6 inches or more to fill a new raised bed.
- Fresh mulch on bare soil: 3 inches, 4 under trees.
- Annual top-up over old mulch: 1 to 2 inches, after raking the old layer loose.
- Gravel, DG and river rock: 2 to 3 inches over fabric.
- Compost as a soil amendment: 1 to 2 inches, then turned in.
Bags or bulk?
Bagged mulch at a big-box store runs $4 to $7 for a 2-cubic-foot bag in 2026, which works out to $55 to $95 per cubic yard. Bulk hardwood mulch from a landscape supply yard is $35 to $60 per yard, plus a delivery fee that is typically $40 to $100 regardless of how much you order. So the crossover is around 2 yards: below that, bags win once you count the delivery fee, and you can haul them in a car. Above it, bulk is cheaper and much less plastic, and by 5 yards you are saving real money.
There is a third option most people forget. Municipal yards and tree services often give away wood chips, and ChipDrop will connect you with an arborist who needs to dump a load. The chips are coarse and mixed, which is fine for paths and around established trees, but not what you want on a front-yard perennial border. Bulk suppliers also sell by the ton for stone, so the calculator converts your volume to weight using typical densities: about 1.4 tons per yard for pea gravel, 1.35 for river rock, 1.5 for decomposed granite, and only 0.4 for hardwood mulch.
| Material | Bulk per cubic yard | Per 2 cu ft bag | Tons per yard |
|---|---|---|---|
| Hardwood mulch | $35 to $60 | $4 to $7 | 0.4 |
| Bark / pine nuggets | $40 to $70 | $5 to $8 | 0.35 |
| Wood chips (arborist) | $20 to $45, often free | $3 to $5 | 0.35 |
| Topsoil | $25 to $50 | $3 to $6 | 1.0 |
| Compost | $30 to $60 | $4 to $8 | 0.5 |
| Pea gravel | $45 to $85 | $5 to $8 (0.5 cu ft) | 1.4 |
| River rock | $60 to $120 | $6 to $10 (0.5 cu ft) | 1.35 |
| Decomposed granite | $40 to $80 | $5 to $9 (0.5 cu ft) | 1.5 |
Ordering without getting burned
Round up. The calculator already rounds bulk orders to whole yards because that is how yards sell it, but add 10 percent on top for a bed with curves or if you have not mulched in a couple of years and the soil has settled. Running short means a second delivery fee or a trip for bags, and the two batches never quite match in color. Leftover mulch keeps for a season under a tarp.
Know what fits where. A cubic yard of mulch weighs 400 to 800 pounds depending on how wet it is and fills a full-size pickup bed level. A yard of gravel is 2,800 pounds and will overload a half-ton truck. Bulk suppliers dump the pile on your driveway, so plan the drop spot close to the beds and lay a tarp first if you care about the concrete. Dyed mulch stains for a few weeks.
Watch the bag size. "2 cubic feet" is the standard, but plenty of bags at the same price are 1.5 cubic feet, and stone bags are 0.5 cubic feet and 50 pounds. The calculator gives counts for 2 and 3 cubic foot bags, and for stone also the 0.5 cubic foot size. Check the label before you multiply.
Now see the bed, not just the number
Upload a photo of your yard, pick a style, and preview it mulched and planted. 3 free designs, no credit card.
Design my gardenFrequently asked questions
How many bags of mulch are in a cubic yard?⌄
A cubic yard is 27 cubic feet, so 13.5 bags of 2 cubic feet or 9 bags of 3 cubic feet. Round up to 14 or 9. If the bags are the smaller 1.5 cubic foot size, it takes 18. Bagged mulch costs roughly 50 to 70 percent more per yard than bulk, but has no delivery fee and you can carry it home in a car.
How much does a yard of mulch cost in 2026?⌄
Bulk shredded hardwood is $35 to $60 per cubic yard at a landscape supply yard, dyed or bark mulch $40 to $70, plus a delivery charge of $40 to $100. Bagged, the same yard costs $55 to $95. Installed by a landscaper, expect $80 to $150 per yard including the material, or about $1 per square foot at 3 inches deep.
How much area does a yard of mulch cover?⌄
It depends on depth. At 3 inches, which is the standard for a new bed, one cubic yard covers 108 square feet. At 2 inches it covers 162 square feet, at 4 inches 81. A quick formula: square feet covered equals 324 divided by the depth in inches.
How do I calculate gravel by the ton?⌄
Work out cubic yards the same way as mulch, then multiply by the density: pea gravel is about 1.4 tons per yard, river rock 1.35, decomposed granite 1.5, crushed stone 1.4 to 1.5. A 200 square foot path with 3 inches of pea gravel is 1.85 cubic yards, or about 2.6 tons. Suppliers quoting by the ton usually round to the half ton.
Should I put landscape fabric under mulch?⌄
Under stone, yes, or the rock sinks into the soil within a couple of seasons and weeds come up through it. Under wood mulch, no. Fabric stops the mulch from breaking down into the soil, which is half the point of mulching, and weed seeds germinate in the decomposed layer on top anyway. Three inches of mulch on bare, weeded soil does the job on its own.