Mulch & Gravel Calculator

How to use the Mulch & Gravel Calculator

1. Choose US or Metric units and pick the material. The density box fills in a typical weight you can change.
2. Choose the shape of the bed or path and enter its size, or enter the area directly if you already know it.
3. Enter the depth you want to spread. Around 2–3 in (5–7.5 cm) is common for mulch; paths and driveways usually need more gravel.
4. Read the bulk volume, the number of bags and the approximate weight, which matters for trailer and truck limits.
5. Optionally add your own bulk price or bag price to compare the cost.

How it works

Volume is area × depth. The calculator converts the depth from inches to feet (or centimeters to meters) before multiplying, then converts the result: 27 cubic feet make a cubic yard and one cubic foot is about 0.0283 m³. Bag counts divide the volume by the bag size (2 or 3 cubic feet, or 50 liters, which is 0.05 m³) and round up to whole bags.

Weight is volume × density. The presets are typical, approximate densities for loose material: for example about 1.4 short tons per cubic yard for gravel and about 0.3 for wood mulch. Moisture makes a big difference, especially for soil, sand and mulch, so treat the weight as a rough guide and use your supplier's figure when you have it.

Example: a 20 × 4 ft bed (80 sq ft) covered 3 in deep holds 80 × 0.25 = 20 cu ft, or 0.74 cu yd. That is 10 bags of 2 cu ft or 7 bags of 3 cu ft. As gravel at 1.4 tons per cu yd it would weigh about 1.04 tons (about 2,074 lb).

Loose material settles and compacts, so many people add 5–10% to the volume, especially for gravel bases that will be tamped down.

Frequently asked questions

How deep should mulch be?
A layer of about 2–3 inches (5–7.5 cm) is a common recommendation for garden beds. Keep mulch pulled back a little from tree trunks and plant stems.

How many bags of mulch make a cubic yard?
A cubic yard is 27 cubic feet, so it takes 13.5 bags of 2 cu ft (buy 14) or 9 bags of 3 cu ft.

How much does a cubic yard of gravel weigh?
Typically around 1.4 short tons (about 2,800 lb), but it varies with the stone type, size and moisture. Check your supplier's figure before loading a trailer or pickup.

Should I buy bags or bulk?
Bags are convenient for small beds. For larger jobs, bulk delivery by the cubic yard is often cheaper per unit. Enter both prices you were quoted to compare.

What does "short ton" mean?
A U.S. short ton is 2,000 lb. In metric mode the weight is shown in metric tonnes (1,000 kg), which is about 1.1 short tons.