Type One Stone Calculator: Convert & Estimate

This calculator converts a weight in type one stone (crushed stone with a nominal top size of 1 inch) from tons to cubic yards, or from cubic yards to tons, using the material’s density. You enter the weight in tons or the volume in cubic yards, and the calculator returns the corresponding volume or weight, plus the total in pounds and cubic feet. The standard density for type one stone is approximately 1.5 tons per cubic yard (about 1.78 tonnes per cubic metre), but you can adjust this value if your supplier uses a different figure.

Formula

The conversion relies on the density of the stone, which is the mass per unit volume. The formulas are:

• To convert tons to cubic yards: Volume (yd³) = Weight (tons) / Density (tons/yd³)
• To convert cubic yards to tons: Weight (tons) = Volume (yd³) × Density (tons/yd³)

Where:

• Weight is the mass of the stone in short tons (US tons, 2000 lb).
• Volume is the space the stone occupies in cubic yards (yd³).
• Density is the bulk density of the stone in tons per cubic yard (tons/yd³). For type one stone, a common value is 1.5 tons/yd³, but it can range from about 1.4 to 1.7 depending on the aggregate’s specific gravity and moisture content.

Worked Example

Using the default values from the calculator: you have 10 tons of type one stone and the density is 1.5 tons per cubic yard.

1. Start with the weight: 10 tons.
2. Divide by the density: 10 ÷ 1.5 = 6.666… cubic yards.
3. Rounded to two decimal places, the volume is 6.67 cubic yards.

This matches the calculator’s output for the default input. If you instead start with 6.67 cubic yards and multiply by 1.5, you get back to 10 tons, confirming the conversion.

What Is Type One Stone?

Type one stone is a crushed aggregate commonly used as a base layer for roads, driveways, patios, and footings. It is graded to have a maximum nominal size of 1 inch (25 mm) and contains a mix of crushed rock and fines (small particles) that compact well. It is often specified as “DTp Type 1” or “MOT Type 1” in the UK, but similar crushed stone with a 1-inch top size is used worldwide under different names. The presence of fines distinguishes it from open-graded gravel, giving it better load-bearing properties when compacted.

The density of type one stone can vary based on the source rock (limestone, granite, basalt) and how much it has been compacted. Loose density is lower than compacted density. The calculator uses a bulk density of 1.5 tons/yd³, which is a typical loose density. If you are measuring compacted stone, the density could be higher, around 1.7 tons/yd³.

How to Use the Calculator

Enter a value in either the weight field (tons) or the volume field (cubic yards). The calculator will compute the missing value and also show the weight in pounds and the volume in cubic feet. For example:

• If you know you need 5 tons of stone, enter 5 in the weight field. The calculator will show the volume as 3.33 cubic yards.
• If you have a space that measures 3 cubic yards, enter 3 in the volume field. The calculator will show the weight as 4.5 tons.

You can also adjust the density if your supplier provides a different figure. For instance, if the stone is very wet, the density might be higher. Always check with your supplier for the exact density if precision matters.

Common Mistakes and Misconceptions

• Mixing tons and tonnes: A short ton (US) is 2,000 lb, while a metric tonne is 1,000 kg (about 2,204 lb). This calculator uses short tons. If you are working in metric tonnes, divide the weight by 1.10231 to get short tons, or adjust the density accordingly.
• Using the wrong density: Type one stone is not the same as pea gravel or large crushed rock. Using a generic density for all aggregates can lead to significant errors. Always use a density specific to the material and its moisture condition.
• Forgetting compaction: When stone is compacted, it settles and the volume decreases. The calculator gives loose volume. If you are ordering stone for a compacted base, you may need to order extra to account for compaction losses, typically 10-15% more.
• Confusing cubic yards with cubic feet: There are 27 cubic feet in a cubic yard. A common mistake is to multiply by 3 instead of 27.

When to Use This Conversion

You need this conversion when ordering aggregate for a project, estimating costs, or planning delivery. For example:

• You are laying a new driveway and the contractor says you need 8 tons of type one stone. You want to know how many cubic yards that is to compare with a supplier who sells by the yard.
• You have a garden path that is 10 feet long, 3 feet wide, and you plan to put down 4 inches of stone. You calculate the volume in cubic feet (10×3×(4/12)=10 ft³), convert to cubic yards (10/27≈0.37 yd³), then multiply by the density to get the weight in tons (0.37×1.5=0.56 tons).

This calculator is also useful for checking if a delivery truck can carry the amount you need, since trucks are often rated by weight.

Limitations of the Formula

The conversion is only as accurate as the density value you use. Density varies with:

• Rock type: Granite is denser than limestone.
• Moisture content: Wet stone weighs more per cubic yard.
• Particle shape and grading: More fines mean a higher density.
• Compaction: Compacted stone has a higher density than loose stone.

For most construction purposes, a density of 1.5 tons/yd³ is a safe average, but for critical projects, you should have the material tested or ask the supplier for a specific gravity value. Also, this calculator does not account for waste or spillage during handling; it is common to add 5-10% to your order.

Frequently Asked Questions

How many cubic yards are in a ton of type one stone?

At a density of 1.5 tons per cubic yard, one ton of type one stone equals approximately 0.67 cubic yards (1 ÷ 1.5 = 0.666…). This is the loose volume. If you are working with compacted stone, the volume would be less because the density is higher.

What is the difference between type one stone and type two stone?

Type one stone has a maximum particle size of 1 inch and contains fines, making it suitable for base layers that need to be compacted. Type two stone is typically a larger, more open-graded aggregate with a top size of 2 inches, used for drainage or as a sub-base where compaction is less critical. The density and cost differ, so always use the correct type for your project.

Can I use this calculator for other aggregates like gravel or crushed concrete?

Yes, as long as you know the density of the specific material. For example, pea gravel has a density of about 1.4 tons/yd³, while crushed concrete may be around 1.3 tons/yd³. Simply adjust the density field to match your material. The calculator works for any bulk material with a known density.

Why does the calculator show a volume of 0 when I enter a weight?

That is because the calculator uses the weight field to compute the volume, but if you also enter a volume, the weight field takes precedence. To get the volume from a weight, leave the volume field empty (0). Similarly, to get weight from volume, leave the weight field empty. The calculator only uses one input at a time to avoid conflicting results.

How much area does one ton of type one stone cover?

It depends on the depth. One ton (0.67 yd³) covers about 54 square feet at 4 inches deep (0.67×27 = 18 ft³, divided by 4/12 ft = 54 ft²). At 2 inches deep, it covers about 108 square feet. Always calculate the volume needed based on your area and depth, then convert to tons.

Is type one stone the same as crusher run?

Crusher run is a similar material that includes larger particles up to 2 inches, while type one stone is specifically graded to a 1-inch top size. Both contain fines and compact well, but type one is often preferred for more precise base work. The densities are similar, so you can use the same conversion with a slight adjustment if needed.

Related

• Video Tracks vs Audio Tracks: Key Differences Explained
• Audi R8 Final Fantasy XV Edition: What Was It?
• Carbon–Bismuth Triple Bonds: What Relativity Changes

in tons | Weight | tons | 10 | 0
in cy | Volume | cubic yards | 0 | 0
out cy_out | Volume (cubic yards) | cubic yards | tons / density | 2
out tons_out | Weight (tons) | tons | cy * density | 2
out lbs | Weight (pounds) | lb | (tons > 0 ? tons : cy * density) * 2000 | 0
out ft3 | Volume (cubic feet) | ft³ | (cy > 0 ? cy : tons / density) * 27 | 0