How do I calculate how much mulch I need?

Multiply the length by the width in feet to get the area, multiply by the depth in inches divided by 12 to get cubic feet, and divide by 27 for cubic yards. A 20 by 10 foot bed with 3 inches of mulch is 50 cubic feet, or 1.85 cubic yards, and about 2 cubic yards with 10% extra.

How deep should mulch be?

Most extension services recommend 2 to 4 inches. A thin layer lets weeds through, and a very deep one can hold too much moisture against plant stems and tree trunks. Keep mulch a few inches away from trunks and stems.

How many square feet does a cubic yard of mulch cover?

A cubic yard covers 324 divided by the depth in inches: 162 square feet at 2 inches, 108 at 3 inches and 81 at 4 inches. The same rule works for gravel, sand and topsoil.

How many bags are in a cubic yard?

A cubic yard is 27 cubic feet, so it equals 13.5 bags of 2 cubic feet, 9 bags of 3 cubic feet or 54 bags of 0.5 cubic feet. Check the size on the bag, since some are sold by weight.

How many tons of gravel are in a cubic yard?

Gravel weighs about 1.4 tons per cubic yard, depending on the stone type and moisture. A load of 5 cubic yards is therefore about 7 tons. Ask your supplier for the exact weight of the product, because it is often sold by the ton.

Is it cheaper to buy in bulk or in bags?

Bulk is usually cheaper per cubic yard once you need about 2 cubic yards or more, but delivery fees and minimums apply and the pile must be moved. Bags cost more per cubic yard and are easier for small jobs. Enter both prices and the calculator compares them.

How much extra should I order?

Add 10% for mulch and 10% to 15% for gravel, sand and topsoil, which compact and settle after you spread them. Order more if the ground is uneven or you are filling a low spot.

🏠 Home & Garden

Mulch, Gravel & Topsoil Calculator · Cubic Yards, Bags and Tons

Landscape materials are sold three ways: by the cubic yard in bulk, by the bag and by the ton. That makes it hard to compare prices or to know how much to order. This calculator takes the size of your bed, path, driveway or lawn and the depth you want, and returns the volume in cubic yards and cubic feet, the number of bags, the approximate weight and the cost for both bulk and bags.

Choose mulch, gravel, sand or topsoil, enter the length and width in feet or the area in square feet, and set the depth in inches. Add 10% extra by default for settling, compaction and uneven ground, a bit more for gravel and soil that pack down. If you buy bags, enter the bag size in cubic feet, usually 2 or 3 for mulch and 0.5 for stone and sand, and the calculator counts whole bags. Prices are examples that you should replace with a quote from your local landscape supplier.

The weights are typical figures for each material and change with moisture and stone type, so ask the supplier for the weight of the product you choose, especially before renting a truck or loading a trailer. For a bed that is round or irregular, find its area with the square footage calculator and use the area option here.

Material

What Do You Know?

Length (feet)

Standard: 20

Width (feet)

For a round or irregular bed, use the square footage calculator and the area option

Depth (inches)

Mulch 2 to 4 in, a gravel path 2 to 3 in, a gravel driveway 4 to 6 in, topsoil for a lawn 4 to 6 in

Extra for Settling and Uneven Ground (%)

Gravel and soil compact, so 10% to 15% is common

Bag Size (cubic feet)

Mulch bags are usually 2 or 3 cu ft; stone and sand bags often 0.5 cu ft. Leave 0 to skip bags

Price per Cubic Yard, Delivered in Bulk ($)

Example price only. Ask your local landscape supplier

Price per Bag ($)

Example price only. Check your store

Project:

Depth:

Bag size:

Detailed Breakdown

9 metrics

PRIMARY RESULT

2.04 cubic yards

Mulch Needed (With Extra)

Area Covered

200 square feet at 3 inches deep

Volume Without Extra

1.85 cubic yards (50.00 cubic feet)

Cubic Feet With Extra

55.00 cubic feet

Bags Needed (2 cu ft Each)

28 bags

Approximate Weight

1,426 lb (0.71 tons)

One Cubic Yard Covers

108 square feet at that depth

Cost in Bulk (Per Cubic Yard)

$91.67

Cost in Bags

$112.00

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exploreReal-World Scenarios

When to Use This Calculator

Everyday financial situations where this tool gives you fast, accurate clarity:

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Mulch a Flower Bed

Get the cubic yards or bags for a 2 to 4 inch layer.

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Order Gravel for a Path or Driveway

See the volume and the approximate tons to tell the supplier.

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Fill a Lawn or Raised Bed With Topsoil

Find the soil needed to a given depth, with extra for settling.

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Compare Bulk and Bags

Check the cost of a bulk delivery against buying bags.

Calculation Formula

Standard Method

Volume (cubic feet) = Area (sq ft) × Depth (in) ÷ 12 Cubic yards = Cubic feet ÷ 27 With extra = Volume × (1 + Extra %) Bags = Cubic feet with extra ÷ Bag size (cu ft), rounded up Weight = Cubic yards × Typical weight per cubic yard One cubic yard covers 324 ÷ Depth (in) square feet Cost in bulk = Cubic yards with extra × Price per cubic yard Cost in bags = Bags × Price per bag Typical weights used: mulch 700 lb, gravel 2,800 lb, sand 2,700 lb and topsoil 2,200 lb per cubic yard. They are planning figures for loose material and vary with moisture and the product. One cubic yard is 27 cubic feet, so it equals 13.5 bags of 2 cubic feet or 54 bags of 0.5 cubic feet.

Benchmark Example:

A 20 ft by 10 ft flower bed with 3 inches of mulch and 10% extra: • Area: 20 × 10 = 200 square feet • Volume: 200 × 3 ÷ 12 = 50 cubic feet = 1.85 cubic yards • With 10% extra: 55 cubic feet = 2.04 cubic yards • Bags of 2 cubic feet: 55 ÷ 2 = 27.5, so 28 bags • Weight: 2.04 × 700 = about 1,426 lb (0.71 tons) • Bulk at $45 a cubic yard: $91.67. Bags at $4 each: 28 × $4 = $112.00 A 30 ft by 3 ft gravel path 3 inches deep needs 24.75 cubic feet with 10% extra, 0.92 cubic yards or about 1.28 tons. A 40 ft by 10 ft gravel driveway base 4 inches deep needs 5.43 cubic yards, roughly 7.6 tons, which is a job for a delivery truck and not for bags.

Frequently Asked Questions

7 answers

Applicable Laws & Regulatory Standards

ASTM International & National Institute of Standards and Technology

Official Legal Reference

ASTM C33/C33M — Standard Specification for Concrete Aggregates

Sets the grading and quality of the sand and gravel used in construction, which is why two products sold as gravel or sand can differ in weight and volume per ton.

ASTM D448 — Standard Classification for Sizes of Aggregate for Road and Bridge Construction

The numbering system for stone sizes, such as No. 57 stone, that suppliers use when you order gravel for a driveway or a base.

NIST Handbook 44, Appendix C — General Tables of Units of Measurement

Defines the cubic yard as 27 cubic feet, the unit this calculator uses to order bulk material, and the ton of 2,000 pounds used to estimate weight.

Legal citations and statutes are provided for consumer transparency, analytical validation, and educational reference under U.S. consumer financial regulations. This tool is not a substitute for formal legal, accounting, or tax counsel.

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