Gravel Calculator
Find out how much gravel you need in cubic yards, tons, and bags. Enter your measurements in feet and inches, choose the kind of stone, and the estimate updates as you type.
Gravel calculator
Gravel paths and beds: at least 2 in, or 4 in if stones or pavers are set into it. Driveways and paver bases: use the depth in your plans.
The sizes below are an example. Type over them with your own.
Allowances
Leave blank to use 10%. Allows for settling into the base and spillage. Clean stone compacts very little.
Leave blank to use 1.40 tons per cubic yard (typical range 1.25 to 1.55). Use your supplier's number if you have it.
Cost (optional)
The cost is your price times the rounded amount in the result, plus delivery. Tax and minimum-order charges are not included.
- Area
- 200 sq ft
- Volume
- 66.7 cu ft2.47 cu yd, before the extra
- Extra
- 10%Adds 6.7 cu ft
- Order quantity
- 2.72 cu yd73.3 cu ft
- Weight
- 3.80 tonsAbout 7,600 lb, at 1.40 tons per cu yd (preset: crushed stone)
- Bags
- 147 bags0.5 cu ft bag, rounded up
How to use the gravel calculator
- Choose the type of gravel. The type sets the weight per cubic yard and the extra percentage, and you can override both.
- Enter the length and width of the area in feet and inches. For a round area, choose Circle and enter the diameter. If you already know the square footage, choose Known area.
- Enter the depth. Inches is the default, and feet is available for deep fills.
- Read the order quantity. To total several areas, such as a path and a patio base, use Add another area. Use Quantity for identical areas.
- Optional: enter the price your supplier quotes, per ton, per cubic yard, or per bag, plus any delivery fee, to see an estimated cost.
Every figure is calculated in your browser. The assumptions behind the result (volume, extra, weight, and bag size) are listed under the main number.
The gravel formula
Cubic feet = length (ft) × width (ft) × depth (in) ÷ 12
Cubic yards = cubic feet ÷ 27
Order = volume × (1 + extra % ÷ 100)
Tons = cubic yards × tons per cubic yard
Bags = cubic feet ÷ cubic feet per bag, rounded up to a whole bag
The calculator carries full precision through every step and rounds only what it displays: cubic yards and tons to two decimals, bags up to the next whole bag.
Worked example: a 20 ft by 10 ft path, 4 inches deep
- Area: 20 × 10 = 200 sq ft.
- Volume: 200 × 4 ÷ 12 = 66.67 cubic feet, which is 2.47 cubic yards.
- Add 10% extra: 66.67 cubic feet becomes 73.33. Divided by 27, that is 2.716, shown as 2.72 cubic yards.
- Weight at 1.40 tons per cubic yard: 2.716 × 1.40 = 3.80 tons, about 7,600 lb.
- Bags of 0.5 cubic foot: 73.33 ÷ 0.5 = 146.67, rounded up to 147 bags.
Cost, with made-up prices. Suppose a supplier quotes $40.00 per ton plus a $75.00 delivery fee. These numbers are only an illustration, not market prices. The cost is 3.80 tons × $40.00 = $152.00, plus $75.00 for delivery, for $227.00. The calculator prices the rounded quantity it shows.
Two areas add together. A 30 ft by 3 ft path and a 10 ft by 10 ft pad, both 4 inches deep, make 190 sq ft and 63.3 cubic feet. With 10% extra, that is 2.58 cubic yards and 3.61 tons.
How much does a cubic yard of gravel weigh?
Suppliers often sell gravel by the ton, but most people measure a job in cubic yards, so the conversion matters. The weights below are for loose material as delivered. Penn State's dirt and gravel road calculator uses the same convention, loose cubic yards and as-shipped US tons.
| Type of gravel | Tons per cu yd | Typical range | Lb per cu ft | Default extra |
|---|---|---|---|---|
| Crushed stone (#57, 3/4 in) | 1.40 | 1.25 to 1.55 | 104 | 10% |
| Pea gravel (3/8 in) | 1.40 | 1.30 to 1.50 | 104 | 10% |
| River rock (1 to 3 in) | 1.35 | 1.20 to 1.50 | 100 | 10% |
| Crusher run or road base | 1.55 | 1.40 to 1.70 | 115 | 25% |
One short ton is 2,000 lb. Real loads vary with the rock, the moisture, and the amount of fine material mixed in.
The EPA's table of volume-to-weight factors lists loose gravel at 2,565 lb per cubic yard (1.28 tons), crushed stone at 100 lb per cubic foot (1.35 tons per cubic yard), and wet gravel at 100 to 120 lb per cubic foot (1.35 to 1.62 tons). Penn State's road calculator uses 1.50 tons for #57 stone. The presets and their ranges sit between these figures. Treat them as planning values and use your supplier's number when you have it.
Crusher run, also called road base or dense-graded aggregate, includes fine material that locks together under a compactor. WisDOT's research report gives 1.75 to 2.1 tons per cubic yard for compacted ¾ inch dense-graded base. The calculator's default of 1.55 tons per loose cubic yard plus 25% for compaction is 1.94 tons per compacted yard, inside that range.
How deep should gravel be?
A University of California Master Gardener guide calls 2 inches a practical minimum for a gravel layer and says to allow 4 inches if thick stones or pavers will be set into it. Quikrete's Quik-Tube guide puts 6 inches of gravel at the bottom of a footing hole for drainage, and its slab guide adds several inches of gravel or crushed stone under concrete where drainage is poor. For anything that carries a load, follow your plans and local code.
| Depth | Sq ft per cu yd | Sq ft per ton (crushed stone) | Tons per 100 sq ft |
|---|---|---|---|
| 1 in | 324 | 231 | 0.43 |
| 2 in | 162 | 116 | 0.86 |
| 3 in | 108 | 77 | 1.30 |
| 4 in | 81 | 58 | 1.73 |
| 6 in | 54 | 39 | 2.59 |
Tons per square foot use 1.40 tons per cubic yard and no extra. Add your extra percentage on top.
The table is a quick check on the calculator. For a 100 sq ft bed at 2 inches, you need 0.62 cubic yards, or 0.86 tons of crushed stone, before extra.
Choosing the right gravel
- Angular stone packs down into a nearly solid surface, so the UC Master Gardener guide considers it the better choice for paths and patios with foot traffic. Decomposed granite is a popular example. The smaller the pieces, the more comfortable the surface is to walk on.
- Rounded gravel, such as pea gravel, never packs down completely. The pieces slip and slide, so the same guide says it suits mulch or ground cover better than a walking surface.
- Crusher run mixes crushed stone with fine material that compacts tightly, which is why its default extra is higher.
Sizes and names vary by region, so confirm the product and its weight with your supplier before you order.
Tips for ordering
- Measure each section of an irregular area separately and add them with Add another area.
- Ask about delivery fees and minimum loads before you round your order to a convenient number.
- Order by the unit your supplier uses to price the material. If they quote per ton, enter the price per ton and compare tons, not yards.
- Bagged gravel usually costs more per cubic foot than bulk, and a cubic yard is 54 half-cubic-foot bags. Bags suit small repairs and tight access.
Frequently asked questions
How do I calculate how much gravel I need?
Multiply length by width (in feet) to get square feet, multiply by the depth in inches, and divide by 12 to get cubic feet. Divide by 27 for cubic yards. Then add 10% for settling and spillage. A 20 ft by 10 ft area at 4 inches deep comes to 2.47 cubic yards, or 2.72 with the extra. The cubic yard calculator explains the steps.
How many square feet does a ton of gravel cover?
At the default crushed stone weight of 1.40 tons per cubic yard, one ton covers about 116 sq ft at 2 inches deep and about 58 sq ft at 4 inches. A University of California Master Gardener article gives a rule of thumb of 80 to 120 sq ft per ton at 2 inches. Lighter or heavier rock moves the answer within that range.
How much does a cubic yard of gravel weigh?
Crushed stone weighs about 1.25 to 1.55 tons per cubic yard (2,500 to 3,100 lb) as it comes off the pile. The calculator uses 1.40 tons for crushed stone and pea gravel and 1.35 for river rock. If your supplier quotes a different figure, type it into the weight field.
How much extra gravel should I order?
The calculator adds 10% for clean stone and 25% for crusher run or road base. Both are planning allowances, not measured values. Clean stone compacts very little, so the 10% mostly covers spillage, uneven ground, and stone that sinks into the soil below. Dense-graded base packs down under a plate compactor, and Penn State's road calculator uses a 25% compaction ratio for dense-graded aggregates. Lower the percentage if your base is firm and level, and raise it if you expect more settling.
How many bags of gravel do I need?
Bagged gravel is commonly sold in 50 lb bags that hold about 0.5 cubic foot (check the label). A cubic yard is 54 of those bags. For the 20 ft by 10 ft example, the calculator shows 147 bags. Past a yard or two, bulk delivery is usually easier than carrying bags.
Sources
- UC Master Gardeners: Gravel pathways in the garden (PDF)
- U.S. EPA: Standard volume-to-weight conversion factors
- WisDOT / WHRP G22-05: Weight-volume relationships and conversion factors for soils and aggregates of Wisconsin (PDF)
- Penn State Center for Dirt and Gravel Road Studies: DGLVR Materials Calculator
- Quikrete sand and gravel products data sheet
- Quikrete: Quik-Tube pillar foundations (project guide with bags per foot of depth)
- Quikrete: Concrete sidewalks and small slabs (project guide)
- NIST Guide to the SI, Appendix B.8: conversion factors (the yard and the cubic yard)