Gravel Calculator
A gravel calculator multiplies area by depth: cubic yards = length × width × depth in feet ÷ 27. A 30 × 3 ft path 3 inches deep needs 30 × 3 × 0.25 = 22.5 cu ft, or 22.5 ÷ 27 ≈ 0.83 cu yd. At a typical 1.316–1.42 tons per cubic yard, that is about 1.1–1.2 tons before any extra.
90sq ft
113.1sq ft
−12.57sq ft
Bags, bulk prices and delivery (optional)
You need 1.76 cu yd (47.63 cu ft) to cover 190.53 sq ft 3 in deep. With 10% extra, order 1.94 cu yd, about 2.55–2.76 tons of gravel ¼–2 in (pea gravel, crushed stone).
| Material | Tons per cu yd | Your order |
|---|---|---|
| Gravel ¼–2 in (pea gravel, crushed stone) | 1.32–1.42 | 2.55–2.76 tons |
| Loose rock (river rock) | 1.29 | 2.49 tons |
| Road base (base course) | 1.25 | 2.43 tons |
| Pit-run gravel | 1.62 | 3.14 tons |
| Sand | 1.45 | 2.81 tons |
Typical loose weights, not guarantees. Moisture, stone size and how the pile is measured change the weight, so ask your supplier for their figure and type it above.
Show steps
- Garden path (rectangle): length 30 ft; width 3 ft. Area = length × width = 30 × 3 = 90 sq ft.
- Round patio (circle): diameter 12 ft. Area = π × diameter² ÷ 4 = π × 12² ÷ 4 ≈ 113.1 sq ft.
- Fire pit (circle, subtracted): diameter 4 ft. Area = π × diameter² ÷ 4 = π × 4² ÷ 4 ≈ 12.57 sq ft.
- Add the areas and subtract the cutouts: 90 + 113.1 − 12.57 ≈ 190.53 sq ft.
- Change the depth to feet: 3 in ÷ 12 = 0.25 ft. Volume = 190.53 sq ft × 0.25 ft ≈ 47.63 cu ft.
- A cubic yard is 3 ft × 3 ft × 3 ft = 27 cu ft, so 47.63 ÷ 27 ≈ 1.76 cu yd (1.349 m³). At 3 in deep, one cubic yard covers 324 ÷ 3 = 108 sq ft.
- Add 10%: 1.76 × 1.1 ≈ 1.94 cu yd to order.
- Weight = volume × weight per cubic yard: 1.94 × 1.316 to 1.94 × 1.42 ≈ 2.55–2.76 tons (5,108–5,511 lb; a US ton is 2,000 lb).
- Bags: 52.4 cu ft ÷ 0.5 cu ft per bag ≈ 104.79, round up to 105 bags.
How to use the gravel calculator
- Pick a shape for each area: rectangle, circle, triangle, trapezoid, half circle, ring, border strip, an irregular four-sided area, or an area you already know.
- Type the sizes in feet and inches (or meters and centimeters). Add more rows for an L-shaped drive or several paths, and use Subtract for a fire pit or shed pad that gets no gravel.
- Enter the depth, choose the material and set the extra allowance for waste and settling.
- Check the weight per cubic yard. The tool fills a typical figure for the material; replace it with your supplier’s number if you have one.
- Optionally open “Bags, bulk prices and delivery” to count bags and compare costs. Open “Show steps” to see all the working.
Gravel formulas: volume and weight
- Area of each shape: rectangle = length × width; circle = π × diameter² ÷ 4; triangle = base × height ÷ 2; trapezoid = (a + b) ÷ 2 × height.
- Volume in cubic feet = area in sq ft × depth in feet. Depth in inches ÷ 12 gives feet, so 3 in = 0.25 ft.
- Cubic yards = cubic feet ÷ 27, because a cubic yard is 3 ft × 3 ft × 3 ft = 27 cu ft. A shortcut: area × depth in inches ÷ 324.
- Weight in tons = cubic yards × tons per cubic yard. A US (short) ton is 2,000 lb.
- Bags = cubic feet ÷ bag volume, rounded up to a whole bag.
In metric: cubic meters = area in m² × depth in cm ÷ 100, and tonnes = m³ × tonnes per m³. One cubic yard is 0.764554857984 m³.
How much does a cubic yard of gravel weigh?
Suppliers sell stone by the ton or by the cubic yard, so you often need to convert. The weight depends on the stone, its size, its moisture and whether it is loose or packed. These are typical loose figures from published government conversion tables:
| Material | Tons per cu yd | Pounds per cu yd | Cu yd per ton | Source |
|---|---|---|---|---|
| Stone or gravel | 1.316 | 2,632.5 | 0.76 | California factors (LA County) |
| Gravel ¼–2 in | 1.42 | 2,840 | 0.70 | New Mexico EMNRD |
| Rock, loose | 1.285 | 2,570 | 0.78 | California factors (LA County) |
| Base course (road base) | 1.25 | 2,500 | 0.80 | New Mexico EMNRD |
| Pit run | 1.62 | 3,240 | 0.62 | New Mexico EMNRD |
| Sand | 1.45 | 2,900 | 0.69 | New Mexico EMNRD |
For pea gravel and crushed stone the calculator uses the 1.316–1.42 span from the first two rows and shows the result as a range. Treat these as typical values, not guarantees. If your quarry says its #57 stone weighs 1.4 tons per yard, type 1.4 in both boxes.
Worked examples
Example 1: a garden path
The path is 30 ft by 3 ft, 3 in deep. Area = 30 × 3 = 90 sq ft. Depth = 3 ÷ 12 = 0.25 ft. Volume = 90 × 0.25 = 22.5 cu ft, and 22.5 ÷ 27 ≈ 0.83 cu yd. With 10% extra, order 0.83 × 1.1 ≈ 0.92 cu yd. At 1.316 to 1.42 tons per yard that is about 1.21 to 1.3 tons. In 0.5 cu ft bags: 24.75 ÷ 0.5 = 49.5, so 50 bags.
Example 2: a driveway
A 50 × 10 ft driveway 4 in deep: 500 sq ft × (4 ÷ 12) ft ≈ 166.67 cu ft, and 166.67 ÷ 27 ≈ 6.17 cu yd. With 10% extra, about 6.79 cu yd, or roughly 8.94 to 9.64 tons of gravel. Ordering by the ton? Multiply that weight by the price per ton. Ordering by the yard? Multiply 6.79 by the price per yard, then round up to what the supplier loads.
Example 3: a round patio around a fire pit
A circle 12 ft across with a 4 ft fire pit in the middle is a ring. Area = π × (12² − 4²) ÷ 4 = π × 128 ÷ 4 ≈ 100.53 sq ft. At 3 in deep: 100.53 × 0.25 ≈ 25.13 cu ft ≈ 0.93 cu yd, or about 1.02 cu yd with 10% extra.
Example 4: an irregular yard
Measure the four sides (30, 22, 28 and 20 ft) and one diagonal (36 ft). The diagonal splits the area into two triangles, and Heron’s formula gives each area from its three sides: about 329.27 and 278.6 sq ft, for a total of about 607.86 sq ft. At 3 in deep that is 607.86 × 0.25 ÷ 27 ≈ 5.63 cu yd, or about 6.19 cu yd with 10% extra.
Quick reference: what a cubic yard covers
One cubic yard (27 cu ft) spread evenly covers 324 ÷ depth in inches square feet:
| Depth | Area per cubic yard | Cubic yards per 100 sq ft |
|---|---|---|
| 2 in | 162 sq ft | 0.62 |
| 3 in | 108 sq ft | 0.93 |
| 4 in | 81 sq ft | 1.23 |
| 6 in | 54 sq ft | 1.85 |
Bags or bulk?
Bagged gravel is easy to carry and suits small jobs such as a post base or a planter. Because there are 54 half-cubic-foot bags in a cubic yard, bags add up quickly on anything larger. Bulk stone is cheaper per yard but usually comes with a delivery fee and sometimes a minimum load. Type the bag price, the bulk price (per ton or per yard) and the delivery fee, and the calculator puts the totals side by side.
Common mistakes
- Mixing inches and feet. 3 in deep is 0.25 ft, not 3 ft. Multiplying by 3 makes the order 12 times too large.
- Dividing by 9 instead of 27. 9 converts square feet to square yards; cubic feet need 27.
- Assuming one ton equals one cubic yard. Most gravel weighs more than a ton per yard, so a 6-yard job needs more than 6 tons.
- Forgetting extra. Uneven ground, settling and spillage eat into the order. The calculator lets you pick the allowance.
- Measuring the diameter as the radius. The circle formula here uses the full distance across.
Real-life uses
Plan a driveway top-up, a patio base, drainage around a foundation (use the border strip shape), a path of stepping stones (subtract the stones), a dog run, or fill around a round fire pit. The same volume math works for sand and road base. Results are estimates; confirm the weight, minimum order and delivery terms with your supplier before you buy.
Sources
- New Mexico EMNRD, Mining and Minerals Division: conversion factors, cubic yards to tons (adapted from BLM Handbook H-3890-1; checked November 2026)
- Los Angeles County Public Works: Converting from Volume to Weight (factors used by the California Integrated Waste Management Board; checked November 2026)
- NIST Handbook 44, Appendix C: general tables of units of measurement (27 cu ft = 1 cu yd = 0.764554857984 m³; short ton = 2,000 lb; checked November 2026)
Gravel volume and weight practice quiz: 10 questions
Test yourself with 10 multiple-choice questions. Choose an answer and press Submit to see if you are right and why. Your score appears at the end.
A cubic yard is 3 ft × 3 ft × 3 ft = 27 cu ft. 9 is the number of square feet in a square yard.
Change 3 in to feet: 3 ÷ 12 = 0.25 ft. Volume = 200 sq ft × 0.25 ft = 50 cu ft. Multiplying by 3 instead of 0.25 gives 600.
Divide by 27: 81 ÷ 27 = 3 cu yd. Dividing by 9 gives 9, which mixes up square and cubic yards.
Weight = volume × weight per yard = 4 × 1.4 = 5.6 tons. Dividing (4 ÷ 1.4 ≈ 2.86) goes the wrong way.
Area = π × 10² ÷ 4 ≈ 78.54 sq ft. Volume = 78.54 × (4 ÷ 12) ≈ 26.18 cu ft. Using 10 ft as the radius gives 104.72.
Triangle area = 12 × 8 ÷ 2 = 48 sq ft. Volume = 48 × 0.25 = 12 cu ft. Forgetting to halve the triangle gives 24.
13 ÷ 0.5 = 26 bags exactly. Dividing by 2 instead of 0.5 gives 6.5, which rounds to 7.
Area = 324 ÷ depth in inches = 324 ÷ 4 = 81 sq ft. 108 sq ft is the figure for 3 in.
Multiply by 1.10: 5 × 1.1 = 5.5 cu yd. Adding 0.1 cu yd is only 2% of 5.
Quiz complete
Frequently asked questions
How much gravel do I need for a 10 × 10 area?
At 3 in deep: 100 sq ft × 0.25 ft = 25 cu ft, which is 25 ÷ 27 ≈ 0.93 cu yd. At 1.316–1.42 tons per yard that is about 1.22 to 1.31 tons before extra.
How many tons are in a cubic yard of gravel?
Typical published figures for gravel run from about 1.3 to 1.4 tons per loose cubic yard. Sand and pit-run material are heavier. Ask your supplier for their figure and type it into the calculator.
How many square feet does a ton of gravel cover?
Divide by the weight per yard first. At 1.42 tons per yard, a ton is about 0.7 cu yd, which covers about 0.7 × 108 ≈ 76 sq ft at 3 in deep.
How many bags of gravel make a cubic yard?
A cubic yard is 27 cu ft, so it takes 54 bags of 0.5 cu ft, or 36 bags of 0.75 cu ft. Check the volume printed on your bag.
How do I measure an irregular area?
Split it into rectangles, triangles and circles and add them, or use the “Irregular, 4 sides” shape: measure four sides and one diagonal, and the calculator applies Heron’s formula to the two triangles.
Related calculators
- Concrete calculator for slabs and footings
- Square footage calculator
- Volume calculator
- Mulch calculator for planting beds
- Weight converter for tons, pounds and tonnes
Related to This Article
More math articles
- The Best Grade 5 Math Book for Massachusetts Students
- 8 Useful Tips on Learning Mathematics Effectively
- A Deep Dive into the Integral Test
- How to Apply Integers Multiplication and Division Rules?
- Using Number Lines to Represent Absolute Value of Integers
- Exponents and Radicals: Rules, Examples, and Practice
- Free Grade 5 English Worksheets for Maine Students
- Exponential and logarithmic integrals Simplified
- FREE 6th Grade MCAS Math Practice Test
- A 4-Week Grade 8 ELA Study Plan: Reading, Writing, Vocabulary, and Review That Actually Fits Real Life
What people say about "Gravel Calculator: Cubic Yards, Tons & Bags (Any Shape)"?
No one replied yet.