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Backyard Review

Free tool

How much mulch, gravel or concrete do I need?

Pick the material, measure the area, and get cubic yards, bags and weight, plus pavers and base for a patio and bags for a slab.

What are you buying?

Area shape

ft
ft

Area: 240 sq ft. For odd shapes, split the yard into rectangles and circles and add the results.

in

Mulch 2–3 in, topsoil for a lawn 4–6 in, a gravel path about 3 in, a raised bed 8–12 in.

%

10% is a common cushion.

Cubic yards

2.44

66 cubic feet

2 cu ft bags

34

rounded up

Approx. weight

0.98 tons

varies with moisture and supplier

Truck or bags?

Bulk

delivery usually beats bags past about 2 cu yd

Bulk material is sold by the cubic yard and delivered by truck. Gravel and soil are heavy, so ask the supplier what a cubic yard weighs before you load a pickup or trailer.

How this is calculated

Volume = area × depth ÷ 12 (inches to feet), plus your waste percentage. One cubic yard is 27 cubic feet. Bags = cubic feet ÷ bag size, rounded up. Pavers = area ÷ one paver's area, plus waste.

Weights are typical figures (mulch about 0.4, topsoil about 1.1, gravel about 1.4 tons per cubic yard) and swing a lot with moisture and the exact product. Concrete bag yields are typical for dry mix: about 0.6 cu ft per 80-lb bag, 0.45 per 60-lb and 0.375 per 50-lb. Check the bag.

Slopes, drainage, frost depth and local codes affect base and slab design. For anything structural, ask a local pro.

Keep going

Quick answers

How do I calculate cubic yards of mulch?

Multiply the length by the width in feet to get square feet, multiply by the depth in inches divided by 12 to get cubic feet, then divide by 27 to get cubic yards. A 200 square foot bed at 3 inches deep is 50 cubic feet, or about 1.9 cubic yards.

How deep should mulch be?

Two to three inches is the usual range. Thicker layers can smother roots and hold too much moisture, and keeping mulch a few inches away from trunks and stems helps prevent rot.

How much gravel do I need for a path or fire pit base?

Work out the area, multiply by the depth in feet (3 inches is 0.25 ft), divide by 27 for cubic yards, and add 10 percent. Gravel weighs roughly 1.4 tons per cubic yard, which matters when you are loading a truck.

How many 80-lb bags of concrete make a cubic yard?

An 80-lb bag yields about 0.6 cubic feet, so a cubic yard (27 cubic feet) takes about 45 bags. At that point, ready-mix delivery is usually easier.

How many pavers do I need for a patio?

Divide the patio area by the area of one paver, then add about 10 percent for cuts and breakage. Twelve-inch pavers cover one square foot each, so a 200 square foot patio needs about 220.

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