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Gravel for a 20x20 Area
A 20 × 20 ft area at 4 inches deep takes about 5.43 cubic yards, or 7.7 US tons, of pea gravel with 10% waste. Adjust the depth and material below.
YOU NEED
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Estimate only. Bag yields, material density and waste vary by product and supplier. Confirm quantities with your supplier and check local building codes before you buy or build.
How much gravel for 20x20?
20 × 20 ft is 400 square feet. At 4 inches deep that is 133.33 cubic feet, or 4.94 cubic yards before waste. With 10% extra, order about 5.43 cubic yards, which is 7.7 US tons (6.9 metric tonnes) of pea gravel at 1.4 tons per yard.
By depth
At 2 inches, for a decorative bed or path, you need 2.72 cubic yards (3.9 tons). At 4 inches, for a patio or shed base, 5.43 cubic yards. At 6 inches, for a driveway, 8.15 cubic yards (11.5 tons). Crushed base you will compact is heavier and needs 10 to 15% more.
Bags or bulk?
A 0.5 cubic foot bag holds about 50 lb of pea gravel. At 4 inches this area would take about 294 bags, so bulk delivery by the ton is usually cheaper above about half a cubic yard.
Frequently asked questions
How many tons of gravel for 20x20?
About 7.7 US tons at 4 inches deep and 3.9 at 2 inches, using pea gravel at 1.4 tons per cubic yard and 10% waste.
How many yards of gravel for 20x20?
5.43 cubic yards at 4 inches with waste, 2.72 at 2 inches.
How accurate is this estimate?
It is a planning estimate, not an order. Bag yields, material density and waste vary by product, supplier and job, so confirm quantities with your supplier and check local building codes before you buy or pour.
Are my measurements saved?
No. Everything is calculated in your browser. Nothing is uploaded or stored.
More free building calculators
Also on this topic: Gravel calculator, Pea gravel calculator, Driveway gravel calculator, Gravel driveway cost.
Common sizes: 10x10 gravel, 10x20 gravel, 12x24 gravel, 20x40 gravel.