General

Mulch, Soil & Gravel Calculator

Work out exactly how much mulch, soil or gravel your beds need in cubic yards, cubic meters and bags.

Imperial (ft / in) Metric (m / cm)

Length ft

Width ft

Depth in

Bag size

Cost per bag

Optional. Leave empty to skip the total cost.

You need

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Enter length, width and depth.

We rounded up by 10% so you do not run out a foot from the end.

What this calculator does

Given the length, width and depth of a flat bed it computes the volume of material you need. Output covers cubic yards (the bulk-delivery unit in North America), cubic meters (the metric standard) and the number of bags at common retail sizes. We round up by 10% by default so you do not run short on the last patch.

How to use it

Measure the longest side, then the perpendicular shortest side. For irregular beds, break the area into rectangles and sum the results. Depth follows the rule of thumb of 2 to 3 inches (5 to 8 cm) for ornamental mulch and 4 inches (10 cm) for weed suppression on bare soil.

How it is computed

Volume = length × width × depth, all in the same unit. We then convert to cubic yards (1 yd³ = 27 ft³) and cubic meters. Bag count = volume in cubic feet ÷ bag size, rounded up. The 10% buffer is applied before rounding so the headline number is the one you should actually buy.

Depth recommendations

Use	Depth
2 cu ft (≈57 L)	2 cu ft (~57 L)
3 cu ft (≈85 L)	3 cu ft (~85 L)
50 L bag	50 L (~1.77 cu ft)
70 L bag	70 L (~2.47 cu ft)

Frequently asked questions

How deep should mulch be?

Two to three inches (5 to 8 cm) is the sweet spot for most ornamental beds. Less and you do not block weeds; more and water has trouble reaching the roots and you can suffocate plant crowns.

Should I order in bags or in bulk?

Bulk delivery is roughly half the price per cubic yard but you need a place to dump it. As a rule of thumb, anything over 6 cubic yards (162 cu ft) is cheaper in bulk, even after delivery fees.

Why does the calculator add 10%?

Because beds are never perfect rectangles, mulch settles and you almost always under-measure depth. The 10% buffer prevents the classic last-trip-back-to-the-store moment.

Does this work for gravel and topsoil?

Yes. The volume math is identical. Just remember that gravel weighs roughly 1.5 short tons per cubic yard while topsoil is closer to 1 ton, which matters if your truck is rated for weight rather than volume.

How big is a 2 cu ft bag in liters?

About 57 liters. A 3 cubic foot bag is about 85 liters. Most North American retailers sell mulch in 2 cu ft bags, while European garden centers sell mulch and bark in 50 to 70 liter bags.

Can I use this for a sloped bed?

If the slope is gentle, measuring the flat footprint is close enough. For steep banks, measure along the slope itself or you will under-buy by the cosine of the angle, around 6% off at a 20-degree slope.

Mulch, Soil & Gravel Calculator