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Mulch Calculator

Figure out how many bags of mulch you need for garden beds, trees, and landscaping. Enter your bed dimensions and depth to get bag counts for 1.5, 2, and 3 cubic foot bags, plus cubic yards for bulk delivery — with an optional bulk price to compare bagged vs. bulk.

Updated 2026-10-01
Bed
ft
ft
in

Refresh 2–3 in · New beds 3–4 in

%

Covers settling and spreading.

$

For bulk delivery comparison

How much does a yard of mulch cover?

Depth Sq ft per yd³ 2 ft³ bags per 100 sq ft
1 in 324 4.2
2 in 162 8.3
3 in 108 12.5
4 in 81 16.7
5 in 65 20.8
6 in 54 25.0
One cubic yard = 27 ft³ = 13.5 two-cubic-foot bags. Coverage = 324 ÷ depth in inches.

How deep should mulch be?

Two to three inches is the sweet spot for most beds — enough to suppress weeds and hold moisture without suffocating roots. Refreshing an existing bed usually needs just 1–2 inches on top of what's left. Around trees and shrubs, keep mulch 3–4 inches deep but pull it a few inches back from trunks and stems; piled-up "mulch volcanoes" rot bark and invite pests.

Bagged or bulk?

One cubic yard equals 13.5 two-cubic-foot bags. Below about a yard, bags win: they're easy to move, store, and return. Above 2–3 yards, bulk delivery from a landscape supplier is usually half the price per yard — the trade-off is a pile on your driveway and a wheelbarrow afternoon. Enter your local bulk price to compare directly.

For irregular beds, split the shape into rectangles, run each one, and add the bag counts — or measure the longest and widest points and accept a little extra.

Bags needed
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Includes waste allowance, rounded up
Or 1.5 ft³ bags
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Or 2 ft³ bags
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Or 3 ft³ bags
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Bed area
—
Volume (cubic feet)
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Volume (cubic yards)
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Volume (cubic meters)
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Bulk order (with waste)
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Estimated bulk cost
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Convert cubic yards ↔ tons for other materials

Common questions

How many bags of mulch do I need?

Multiply the bed area in square feet by the depth in inches, divide by 12 for cubic feet, then divide by the bag size. A 10 × 10 ft bed at 3 inches is 25 cubic feet: 13 bags of 2 cubic feet, 9 bags of 3 cubic feet, or 17 bags of 1.5 cubic feet.

How much mulch do I need?

Multiply the bed area in square feet by the depth in feet, then divide by 27 for cubic yards. A 300 sq ft bed at 3 inches deep is 300 × 0.25 = 75 cubic feet, or about 2.8 cubic yards — roughly 38 two-cubic-foot bags.

How much mulch do I need?

How many bags of mulch are in a cubic yard?

A cubic yard is 27 cubic feet, so it takes 13.5 bags at 2 cubic feet each, 9 bags at 3 cubic feet, or 18 bags at 1.5 cubic feet. Bulk mulch is usually cheaper per yard once you are past about 10 to 12 bags.

How much area does a yard of mulch cover?

About 162 sq ft at 2 inches deep, 108 sq ft at 3 inches, or 81 sq ft at 4 inches. At 1 inch, a cubic yard spreads over 324 sq ft, but that is too thin to suppress weeds.

How deep should mulch be?

2 to 3 inches suits most beds, and 3 to 4 inches is better where you need weed suppression. Deeper than 4 inches can hold water against roots and starve the soil of air, and mulch should never be piled against tree trunks or stems.

Is bagged or bulk mulch cheaper?

Bulk is almost always cheaper per cubic yard, but adds a delivery fee and needs somewhere to dump it. Enter your bulk price per yard in the calculator to compare it against the bag count for the same bed.

How this is calculated

Method
Volume = length × width × depth, with dimensions normalized to feet (or meters in metric mode).
Order quantity = volume × (1 + waste allowance) to cover settling and uneven spreading.
Bags = order volume ÷ bag size (1.5, 2, or 3 ft³), rounded up to whole bags.
Bulk cost = order quantity in cubic yards × your price per cubic yard, when a price is provided.
Assumptions
  • Assumes a rectangular bed with uniform depth; measure irregular beds as multiple rectangles and add the results.
  • The default 5% waste allowance covers settling and spreading losses.
  • A depth of 2–3 in refreshes an existing bed; 3–4 in suits a new bed. Depths above 4 in can suffocate plant roots.
  • One cubic yard covers 324 ÷ depth (in inches) square feet: 324 sq ft at 1 in, 162 at 2 in, 108 at 3 in, 81 at 4 in. It equals 13.5 two-cubic-foot bags.
Sources
  • University extension mulching guidance (e.g. USDA / state extension services) — Recommended 2–4 in mulch depth; deeper layers risk root suffocation and pest issues.
Methodology reviewed 2026-10-01 · See our methodology for how we build and test calculators.
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