Free tool · from a working landscape crew
Mulch and topsoil calculator
Enter your bed or lawn area and depth and get the cubic yards of mulch, topsoil or compost to order, or the number of 2 and 3 cu ft bags to buy.
Enter an area and depth greater than zero.
In central PA? Our crews edge, mulch and topsoil beds and lawns. See our landscaping.
How it works
Area × depth in feet (inches ÷ 12) = cubic feet. Cubic feet ÷ 27 = cubic yards, the unit bulk yards sell mulch and soil by.
Cubic feet ÷ 2 for 2 cu ft bags and ÷ 3 for 3 cu ft bags, rounded up. A cubic yard is 13.5 two-foot bags or 9 three-foot bags.
One cubic yard covers 324 sq ft at 1 in. deep, so divide 324 by your depth: 162 sq ft at 2 in., 108 at 3 in., 81 at 4 in.
100 sq ft bed at 3 in. of mulch: 100 × (3 ÷ 12) = 25 cu ft
25 ÷ 27 = 0.93 cu yd · 25 ÷ 2 = 12.5 → 13 bags (2 cu ft) · 25 ÷ 3 = 8.3 → 9 bags (3 cu ft)
How deep to spread it
| Material | Depth | Notes |
|---|---|---|
| Organic mulch (shredded bark, wood chips) | 2–4 in. | Less on poorly drained soil. More than 4 in. may harm tree roots. Pull mulch 3–5 in. back from young trees and 8–10 in. from mature trees. |
| Fine or double-shredded mulch | 1–2 in. | Penn State’s lower depth for finely textured mulch. |
| Topsoil for a new lawn | 4–6 in. | Minimum firmed, settled depth of good-quality topsoil. Ideally mix 2 in. of it into the top 2–3 in. of subsoil first. |
| Compost for a new lawn | 1–2 in. | Worked 4–6 in. into the soil. Layers over 2 in. are hard to till in evenly. |
Depths from Penn State Extension: Mulching Landscape Trees and Lawn Establishment. Topsoil and compost settle, so the calculator lets you add a percentage for settling.
Related guides: topsoil vs fill dirt and hardwood mulch vs color-enhanced mulch.
Questions
How much area does a yard of mulch cover?
One cubic yard is 27 cubic feet, which covers 324 square feet at 1 inch deep. Divide 324 by your depth: 162 square feet at 2 inches, 108 at 3 inches and 81 at 4 inches.
How deep should mulch be?
Penn State Extension recommends a 2 to 4 inch layer of organic mulch, less on poorly drained soil, and 1 to 2 inches of finely textured or double-shredded mulch. More than 4 inches may harm a tree’s roots. Keep mulch off the trunk: pull it back 3 to 5 inches from young trees and 8 to 10 inches from mature ones.
How many bags of mulch are in a yard?
A cubic yard is 27 cubic feet: 13.5 bags of 2 cubic feet (buy 14) or 9 bags of 3 cubic feet.
How much topsoil do I need for a new lawn?
Penn State Extension calls for at least 4 to 6 inches of good-quality topsoil, measured firmed and settled. A 1,000 square foot lawn at 4 inches takes 12.3 cubic yards.
How much compost should I add to my soil?
For a new lawn, Penn State Extension suggests a 1 to 2 inch layer of compost worked 4 to 6 inches into the soil. Layers thicker than 2 inches are hard to till in evenly. One inch over 324 square feet is one cubic yard.
How much does a yard of topsoil weigh?
Lorusso Corp.’s conversion chart lists screened loam at 1.10 tons per cubic yard and compost at 0.50 tons per cubic yard, as loaded in the truck. Wet soil weighs more.
Sources: Penn State Extension, Mulching Landscape Trees (2–4 in. organic mulch; 1–2 in. fine or double-shredded; more than 4 in. may harm roots; 3–5 in. and 8–10 in. trunk clearance); Penn State Extension, Lawn Establishment (4–6 in. topsoil; 1–2 in. compost worked 4–6 in. deep; layers over 2 in. hard to till evenly); Lorusso Corporation conversion chart (screened loam 1.10 and compost 0.50 tons per cu yd, as loaded). 1 cu yd = 27 cu ft; 1 cu ft = 0.0283 m³.
Groundwork Design Co. · designed by builders
Plan the beds before you buy the mulch
Our online landscape plans lay out beds, plants, edging and lawn areas to scale, with quantities, so you buy the right amount the first time. Plans from $349, anywhere in the U.S.
See design packagesAll free calculatorsIn central PA? We do the beds, topsoil and grading for you. See our landscaping and grading and site work.
Muthler Landscaping & Construction LLC · 913 Bellefonte Ave, Lock Haven, PA 17745 · (570) 397-9800 · PA HIC #PA212584.