Number 7 Stone Cubic Yards to Tons
- Cubic yards
- 3 yd³
- You entered
Number 7 stone (also called #7 gravel or pea gravel) weighs about 1.4 tons per cubic yard when dry, so 1 cubic yard = 1.4 tons, and 1 ton = about 0.71 cubic yards. Enter your cubic yards below to get the weight in tons for typical dry, loose #7 stone.
Formula
The conversion uses the bulk density of #7 stone. The formula is:
Tons = Cubic Yards × 1.4
- Tons – weight in short tons (US tons, 2,000 lb)
- Cubic Yards – volume of stone
- 1.4 – average density factor for dry, loose #7 stone (tons per cubic yard)
If you need metric: 1 cubic yard ≈ 1.17 metric tonnes (1.4 tons × 0.907). The calculator above uses the US short ton.
Worked Example
Using the default of 3 cubic yards:
- Start with the volume: 3 yd³
- Multiply by the density factor: 3 × 1.4 = 4.2
- Result: 4.2 tons
So 3 cubic yards of #7 stone weighs about 4.2 tons. That matches the calculator output.
What Is Number 7 Stone?
Number 7 stone is a crushed stone aggregate with a nominal size of about 3/8 inch (9.5 mm) down to fine dust. It is commonly sold as “pea gravel� when rounded, or as crushed granite or limestone in angular form. It is used for drainage layers, pipe bedding, walkways, and as a base material for pavers. The small size makes it easy to spread and compact, but it can shift under heavy loads if not contained.
Why Does Density Vary?
The 1.4 tons per cubic yard is a typical average, but the actual weight depends on several factors:
- Moisture content – wet stone can weigh up to 10% more
- Rock type – granite is denser than limestone
- Fines content – more dust fills voids and increases weight
- Compaction – loose stone weighs less than compacted stone
For most landscaping and construction estimates, 1.4 tons/yd³ is safe. If you need exact weights for structural engineering, ask your supplier for the specific bulk density of the material they provide.
How to Convert Cubic Yards to Tons Manually
If you don’t have a calculator handy, follow these steps:
- Measure the length, width, and depth of the area in feet.
- Multiply length × width × depth to get cubic feet.
- Divide by 27 to get cubic yards (since 1 yd³ = 27 ft³).
- Multiply cubic yards by 1.4 to get tons.
Example: a 10 ft × 10 ft area, 4 inches deep (0.333 ft):
- Volume = 10 × 10 × 0.333 = 33.3 ft³
- Cubic yards = 33.3 ÷ 27 = 1.23 yd³
- Tons = 1.23 × 1.4 = 1.72 tons
Common Mistakes and How to Avoid Them
- Mixing up tons and cubic yards – tons measure weight, cubic yards measure volume. Always convert using density.
- Using the wrong ton – US short ton is 2,000 lb, UK long ton is 2,240 lb, metric tonne is 1,000 kg. This calculator uses US short tons.
- Forgetting to convert inches to feet – depth in inches must be divided by 12 first.
- Ignoring compaction – if you compact the stone, it will settle and you may need more material than the loose volume.
How Much Do I Need for My Project?
To estimate how many tons of #7 stone you need, first determine the volume in cubic yards. For a rectangular area, use the formula above. For a circular area, use π × radius² × depth. Then multiply by 1.4 to get tons.
Typical projects and approximate amounts:
- Walkway (4 ft wide, 10 ft long, 3 in deep) – about 0.37 yd³, or 0.52 tons
- Drainage trench (1 ft wide, 20 ft long, 1 ft deep) – about 0.74 yd³, or 1.04 tons
- Paver base (10 ft × 10 ft, 4 in deep) – about 1.23 yd³, or 1.72 tons
Always order 10–15% extra to account for settling and waste.
Frequently Asked Questions
How many tons are in a cubic yard of #7 stone?
On average, 1 cubic yard of dry, loose #7 stone weighs about 1.4 tons (2,800 lb). Wet stone can weigh up to 1.5 tons per cubic yard.
Can I use #7 stone for a driveway?
Yes, but it is better as a top layer or for pathways. For a driveway base, larger stone like #57 is often used because #7 can shift under vehicle weight. If you use #7, compact it well and consider a binder.
How many cubic yards are in a ton of #7 stone?
Divide 1 by the density: 1 ÷ 1.4 = 0.714 cubic yards per ton. So a ton covers about 0.71 yd³.
What is the difference between #7 and #57 stone?
#7 stone is smaller (about 3/8 inch) and contains more fines. #57 stone is larger (about 1 inch) and has fewer fines, making it better for drainage and as a base. #7 is often used for decorative paths or as a final layer.
Does the calculator account for moisture?
No, it assumes dry, loose stone. If your stone is wet, add 5–10% to the weight. For critical projects, ask your supplier for the exact density.