Landscaping
Mulch Calculator
Enter your bed dimensions in feet and the mulch depth in inches to get the volume in cubic yards and the number of bags to buy, with an optional cost estimate.
Formula tested · Local units · No sign-up
Project inputs
Enter measurements
Use your preferred units. Results update automatically.
Show the calculation methodFormula, conversions, rounding, and assumptions+
Volume = bed area × depth. Because depth is in inches while the bed is measured in feet, the calculator converts first — a 3-inch layer is 0.25 ft, so a 120 sq ft bed needs 120 × 0.25 = 30 cubic feet.
US mulch is sold two ways: by the bag (2 cubic feet is a common size — check your product) or in bulk by the cubic yard (27 cubic feet). The calculator shows both, rounding bags up to whole bags.
Real-world example
Worked example: 10 ft × 12 ft bed, 3 in deep
- Area: 10 × 12 = 120 square feet.
- Convert depth: 3 in ÷ 12 = 0.25 ft.
- Volume: 120 × 0.25 = 30 cubic feet.
- Add 5% wastage: 30 × 1.05 = 31.5 cubic feet (= 1.17 cubic yards).
- Bags: 31.5 ÷ 2 = 15.75, rounded up to 16 bags of 2 cu ft.
Buy 16 bags of 2 cu ft. At an example price of $4.00 per bag, that's $64.00.
Before you start
How to measure
- Measure bed length and width in feet at the widest points; for irregular beds, split into rectangles and add the areas, then use the total-area mode.
- Pick a depth for the job: a 2–3 inch layer is typical for topping up, 3–4 inches for new beds and weed suppression.
- Keep mulch a few inches away from trunks and stems — measure the bed area you'll actually cover, not the full planting footprint.
Local guidance
Notes for United States
- US retail mulch is usually bagged in cubic feet (2 cu ft is common, 1.5 and 3 cu ft also exist) — check the bag before relying on the default.
- Bulk mulch from landscape yards is sold by the cubic yard; above roughly a yard, bulk delivery often beats hauling bags.
- Sales tax varies by state and locality; bag prices on the shelf normally exclude it.
Quick reference
Mulch depth quick reference (typical planning values)
| Application | Common depth |
|---|---|
| Annual top-up of existing beds | 1–2 in |
| General beds and borders | 2–3 in |
| New beds / weed suppression | 3–4 in |
| Around trees (clear of trunk) | 2–4 in |
Planning values only — deeper isn't always better; over-mulching can suffocate roots.
Good to know
Common mistakes to avoid
- Multiplying square feet by inches without converting — this overstates volume by 12×.
- Assuming every bag is 2 cubic feet: sizes vary by brand and material, and bark nuggets, shredded hardwood and dyed mulch all come in different bag sizes.
- Skipping the wastage allowance — mulch settles and spreads unevenly, so 5% extra is a sensible buffer.
- Measuring the whole yard instead of just the beds being covered.
Need help?
Frequently asked questions
How many 2 cu ft bags make a cubic yard?
A cubic yard is 27 cubic feet, so 27 ÷ 2 = 13.5 — you'd need 14 bags to cover what one bulk cubic yard covers. That ratio is the quickest way to compare bag and bulk pricing.
How much mulch for 200 square feet at 3 inches?
200 × 0.25 = 50 cubic feet. With 5% wastage that's 52.5 cubic feet, or 1.94 cubic yards — 27 bags of 2 cu ft (52.5 ÷ 2 = 26.25, rounded up).
Should I buy bags or bulk?
Bags are easier to handle and store; bulk is usually cheaper per cubic yard and avoids plastic waste. Run the calculator, then compare the bag total against your landscape yard's bulk quote — enter your supplier's prices, as they vary by material and region.
Keep planning
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About this calculator
- Written by:
- BuildMeasure Editorial Team
- Technically reviewed by:
- Pending independent technical reviewer (formula unit-tested; see methodology)
- Last reviewed:
- 2026-07-16
- Formula version:
- 1.0.0
- Region reviewed for:
- United States
- Spotted an error?
- Report a correction
Methodology
- Volume is computed as bed area × depth. You can enter the area directly or as length × width; either way all inputs are converted to SI units (metres) before any arithmetic to avoid unit drift.
- The wastage allowance is applied to the exact volume to cover settling and uneven spreading.
- Bag counts divide the total volume by the bag size you enter and round UP to whole bags, because you can't buy a fraction of a bag. The default bag size is a clearly-labelled common retail size (2 cubic feet in the US, 50 litres elsewhere) and is fully editable.
- The cost estimate simply multiplies the bag count by the price you enter. No prices are built in.
- The formula is covered by automated unit tests, including hand-calculated worked examples, and is versioned (see formula version on this page).
Sources & standards
- Unit definitions: 1 ft = 0.3048 m and 1 yd³ = 27 ft³ (exact definitions).
- Bag sizes: 2 cu ft is a common US retail mulch bag size, used as an editable default — check your product.
This tool provides a material estimate for planning purposes only. It is not a quotation. Bag sizes and coverage vary by product, and mulch settles over time — confirm quantities and product sizes with your supplier before buying.