Length and width tell you the area. Depth tells you how much gravel to order. Enter all three, then use your supplier’s bulk density to turn that volume into a weight.
Weights here are US short tons of 2,000 lb. The 50 lb bag estimate uses the same density, so the two ways of buying stay consistent.
How to use this calculator
- Measure the area, breaking an irregular driveway into rectangles if needed.
- Set the depth for the job — surface dressing and structural layers are different depths.
- Choose the density closest to your stone, or ask the supplier for theirs.
- Order in whole tons or yards as your supplier sells, rounding up: running short mid-driveway is worse than a small leftover pile.
How gravel quantities are calculated
Volume in cubic feet = length x width x (depth in inches / 12). Cubic yards = cubic feet / 27. US short tons = cubic yards x density. Each US short ton is 2,000 lb, so 50 lb bags = total US tons x 2,000 / 50, rounded up. Bag count uses the same density as the bulk weight.
A 20 ft x 10 ft driveway refreshed 3 inches deep needs 50 cubic feet: about 1.85 cubic yards, weighing about 2.59 US short tons at 1.4 US tons per cubic yard. That is a small bulk delivery, or 104 individual 50 lb bags rounded up.
A few things worth checking
- Ordering gravel by area with no depth, so a 'driveway load' arrives sized for a path.
- Skipping the compacted base layer on driveways and putting all the depth into loose surface stone, which ruts and migrates.
- Forgetting delivery weight limits — a 10-ton load on a weak residential driveway can crack it; split loads if unsure.
Your questions, answered
How much gravel does a 20x10 ft area need?
At an entered depth of 3 inches, the tool calculates 50 cubic feet or about 1.85 cubic yards. At the selected density of 1.4 US short tons per cubic yard, that is about 2.59 US short tons. These inputs are an example, not a driveway design.
How many tons are in a cubic yard of gravel?
That depends on the density of the material supplied. The calculator starts at 1.4 US short tons per cubic yard and lets you change it. Use a density supplied for the actual aggregate rather than treating the starting value as universal.
Does the calculator include a base layer?
It estimates only the rectangular layer whose length, width and depth you enter. It does not design a driveway, choose a base or calculate compaction. Estimate separate layers separately and check the site-specific specification.
Which kind of ton does it use?
It uses the US short ton of 2,000 lb. The 50 lb bag comparison uses that same unit. A metric tonne or UK long ton is a different unit, so check the unit on a supplier quote before comparing quantities.
A Simple Materials Checklist for Your Next DIY Project
Keep the measurements, materials and small forgotten bits on one page before you shop.