How much does a yard of mulch cover?

One cubic yard of mulch covers 162 sq ft at 2 inches deep, 108 sq ft at 3 inches, and 81 sq ft at 4 inches. The math: a yard is 27 cubic feet, so coverage = 27 ÷ (depth in feet). At the standard 3-inch depth, plan on roughly 100 sq ft per yard.

How deep should mulch be?

Use 2–3 inches in flower and shrub beds — enough to hold moisture and block most weeds without smothering roots. Go 3–4 inches around trees and in paths for stronger weed suppression, but always keep mulch 3–6 inches away from trunks and stems. Over 4 inches can starve roots of oxygen and harbor pests.

Is bulk mulch cheaper than bags?

Almost always, once you need about 1 to 1.5 cubic yards. A 2 cu ft bag at $4 works out to $54 per yard, while bulk mulch typically runs $25–50 per yard plus a delivery fee. Below one yard, bags usually win because there is no delivery charge and no pile to shovel; above 1.5 yards, bulk wins clearly.

How many bags of mulch are in a cubic yard?

A cubic yard is 27 cubic feet, so it equals 13.5 bags of 2 cu ft or 9 bags of 3 cu ft. If a project needs 2 yards, that is 27 two-cubic-foot bags — at that point a bulk delivery is usually much cheaper and saves a lot of lifting.

How often should mulch be replaced?

Organic mulch (hardwood, pine bark, cedar) breaks down and typically needs a 1-inch top-up every year and a full 2–3 inch refresh every 2–3 years. Before adding more, rake the old layer to break up crusting — and never let the total depth creep past 4 inches.

Mulch Calculator

Name: Mulch Calculator
Author: Miikka

Enter your bed dimensions in feet (or the square footage directly), pick a depth, and see exactly how much mulch to buy — in cubic yards for bulk delivery and in 2 and 3 cubic foot bags for the home center. Add prices to compare bulk vs bagged before you order.

By Miikka · CalcBrew · Updated Aug 27, 2026

Length (ft)

Width (ft)

Mulch depth

Bulk price per yard ($, optional)

Price per 2 ft³ bag ($, optional)

120 sq ft at 3" deep needs

Cubic yards

1.11

Cubic feet

2 ft³ bags

3 ft³ bags

Coverage: 1 cubic yard of mulch covers

Depth	Coverage per yard	Typical use
2 inches	162 sq ft	Flower beds, refresh
3 inches	108 sq ft	Standard new bed
4 inches	81 sq ft	Weed suppression, trees

📌 Never pile mulch against tree trunks ("volcano mulching") — keep a 3–6 inch gap around the trunk so the bark stays dry and pest-free.

How much mulch do I need?

cubic yards = area (sq ft) × (depth (in) ÷ 12) ÷ 27

Worked example: a 10 ft × 12 ft bed (120 sq ft) mulched 3 inches deep needs 120 × 0.25 = 30 cubic feet, which is 30 ÷ 27 ≈ 1.11 cubic yards — or 15 bags of 2 cu ft (30 ÷ 2, rounded up). At that quantity, a bulk yard-and-a-half delivery is usually cheaper than bags.

Recommended depth by use

Flower and perennial beds: 2–3 inches. Enough to retain moisture and suppress weeds; deeper layers can smother shallow roots and self-seeding plants.
Around trees and shrubs: 3–4 inches in a wide, flat ring — but never against the trunk. So-called volcano mulching traps moisture against the bark and invites rot, insects and girdling roots. Keep a 3–6 inch gap.
Paths and open areas: 3–4 inches of coarse mulch for maximum weed suppression and durability.

When to mulch: the best windows are mid-to-late spring (after the soil has warmed) and fall (to insulate roots for winter). Avoid mulching very early in spring — it keeps cold soil cold and slows growth.

Frequently asked questions

Cite this calculator

APACalcBrew. (2026). Mulch Calculator. https://calcbrew.com/mulch-calculator

MLA“Mulch Calculator.” CalcBrew, 2026, calcbrew.com/mulch-calculator.

Link to https://calcbrew.com/mulch-calculator. Results are estimates; cite the underlying formula or data source for academic work.

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