Material estimator

Mulch Calculator

Calculate mulch volume in cubic yards, cubic feet, bags, and bulk cost for mulch beds and landscape areas.

Reviewed for formula logic and buying assumptions on May 21, 2026.

How This Calculator Works

Use this page to calculate mulch volume before buying bags or ordering bulk delivery. Mulch is sold by the bag or cubic yard, while garden beds are measured in feet and inches, so the calculator converts bed size and depth into both buying units.

Formula

To calculate mulch volume: cubic feet = length x width x mulch depth in feet. Cubic yards = cubic feet / 27. Bags = cubic feet / bag size, rounded up.

Assumptions

Most garden beds use 2-4 inches of mulch. Refresh layers are usually thinner than new beds. Do not pile mulch against tree trunks or plant stems.

Measurement Checklist

Measure each bed area and choose depth before comparing bags and bulk yards.
Use a thinner depth for refresh layers and a deeper depth for new beds or weed suppression.
Keep mulch away from trunks, stems, siding, and foundation contact points.
Convert bag size to cubic feet before comparing bagged mulch with bulk cubic-yard pricing.

Practical Examples

A 20 ft by 10 ft bed at 3 inches deep needs 50 ft^3, or 1.85 yd^3. With 10% overage, buy about 28 two-cubic-foot bags.
To calculate mulch volume for a 10 ft by 12 ft bed at 2 inches deep with 10% settling, plan about 0.81 yd^3, or about 11 two-cubic-foot bags.
A 40 ft by 5 ft border at 3 inches deep with 10% settling needs about 2.04 yd^3, or about 28 two-cubic-foot bags.
Refreshing 300 sq ft at 1.5 inches deep with 5% settling needs about 1.46 yd^3, or about 20 two-cubic-foot bags.

Before You Buy

Buying Guidance

Calculate mulch volume before comparing bulk and bag pricing so both options are in the same cubic-foot or cubic-yard unit.
Bulk mulch is usually cheaper for larger beds, while bags are easier for small areas, limited hauling space, or staged work.
Two-cubic-foot bags are common at garden centers, but bag size varies. Use the size printed on the product you plan to buy.
A refresh layer is usually thinner than a new bed, so change depth before comparing bag and bulk cost.

Waste Rules

Use a modest overage because mulch settles after watering, weather, and spreading.
Use less depth around existing perennials and more depth for new open beds where weed suppression is the goal.

Common Mistakes

Do not bury plant crowns or pile mulch against trunks, stems, siding, or foundation contact points.
Do not calculate mulch volume from square feet alone; depth is what turns area into cubic feet.
Do not compare bulk and bag prices without converting both to cubic yards or cubic feet.

Plan the Rest of the Job

Common Questions

How do I calculate mulch volume?

Measure the bed length and width in feet, choose the mulch depth in inches, convert depth to feet, then multiply length x width x depth. Divide cubic feet by 27 for cubic yards.

How deep should mulch be?

Many beds use 2-3 inches for refreshes and 3-4 inches for new beds or stronger weed suppression.

Is bagged or bulk mulch cheaper?

Bulk is usually cheaper for larger areas, while bags are easier for small beds and limited hauling capacity.

Should I include settling?

Yes. Mulch can settle after watering and weather, so a modest overage is practical.