Crushed Stone Calculator

Crushed Stone Calculator: How Much Do You Really Need?

Ordering crushed stone sounds easy until you are standing in the yard with a measuring tape and a dozen questions. Do you buy by the ton or by the cubic yard? How deep should the layer be? Does the stone shrink when you pack it down? Get it wrong and you either run out halfway through the job or end up with a pile of extra stone you have to move by hand.

This crushed stone calculator takes care of the math. Enter the size of your area, choose the type of stone and how deep you want it, and you get the volume, the weight in tons, the number of truck loads and an estimated cost. It works for a driveway base, a garden path, a patio, a shed pad, a French drain or a decorative bed.

You can switch between feet and metres, add more than one layer (for example a thick base and a thin top layer), and change the prices to match what your local supplier charges. It is free, it needs no sign-up, and it updates as you type.

How to Calculate Crushed Stone

The basic idea is simple. First you find the volume of the space you want to fill. Then you add a little extra, because loose stone gets packed down. Finally you turn that volume into weight, because most suppliers sell crushed stone by the ton.

Here is an example. Say you are building a path that is 3 feet wide and 30 feet long, and you want a 4 inch base. The area is 3 x 30 = 90 square feet. Four inches is one third of a foot, so the volume is 90 x 0.33 = 30 cubic feet. Divide by 27 to get cubic yards, and you have about 1.1 cubic yards.

Now add 15 percent for compaction and 5 percent for waste and spillage. That brings you to about 1.34 cubic yards. Crushed stone weighs roughly 1.4 tons per cubic yard, so you need close to 1.9 tons. A good supplier will tell you the exact weight of the stone they sell, so it is worth asking.

For a bigger job, a driveway base of 12 x 50 feet at 6 inches deep, using crusher run at about 1.5 tons per cubic yard, comes out at around 20 tons after compaction and waste. That is about two truck loads, which is why checking the numbers before you call the supplier matters.

How to Use This Calculator

Start at the top and work your way down. There is nothing to memorise. If you are not sure about a setting, the default is a sensible starting point for the project you picked.

• Pick a project type, such as driveway base, walkway, patio, French drain, shed pad or decorative bed. This sets a typical depth, stone type and compaction rate for you.
• Enter your measurements. You can add up to six sections, and each one can be a rectangle, a circle or a triangle. That makes it easy to cover odd shapes.
• Set the depth of each layer and choose the stone type. Add a second or third layer if your design needs one.
• Check the compaction and waste percentages. Higher numbers are safer if your ground is uneven.
• Type in the price you were quoted per ton or per cubic yard. Switch on delivery, fabric, edging, labor or a compactor rental if you want a full project cost.
• Read the results, look at the charts, and copy the summary or download the CSV to share with your supplier.

How Much Does Crushed Stone Weigh?

Weight is the part that confuses most people. A cubic yard is a measure of space, not weight, and different stones weigh different amounts. As a rough guide, crushed stone weighs between 1.2 and 1.5 tons per cubic yard, which is about 2,400 to 3,000 pounds. Finer material and crusher run weigh more because the small pieces fill the gaps between the larger ones.

These are the typical figures this calculator uses. They are close to what many suppliers quote, but moisture and the quarry make a difference, so always check with your own supplier.

• Crusher run or road base: about 1.5 tons per cubic yard
• #57 clean stone: about 1.4 tons per cubic yard
• #3 stone: about 1.35 tons per cubic yard
• #8 stone: about 1.4 tons per cubic yard
• Screenings or stone dust: about 1.5 tons per cubic yard
• Pea gravel: about 1.45 tons per cubic yard

Types of Crushed Stone and What They Are Used For

Not all crushed stone is the same, and picking the wrong type is one of the most common mistakes. The names can sound confusing, but the idea is simple. The number tells you the size of the pieces, and some mixes include fine dust that helps the stone lock together.

Crusher run, also called road base or 3/4 minus, is a mix of stone and fine dust. It packs down hard, which makes it a favourite for driveway, path and patio bases. Clean stone like #57 has no dust at all. The gaps between the pieces let water drain through, so it is the usual choice for French drains and for the layer under a concrete slab.

The larger #3 stone is good for thick bases on soft ground. The small #8 stone works well as a bedding layer under pavers. Screenings, or stone dust, give a smooth top layer for paths. Pea gravel is a little different, because it is rounded rather than crushed, but it is often grouped with crushed stone for garden paths and play areas.

How Deep Should the Stone Layer Be?

Depth depends on the job and on the ground underneath. These are common starting points, not strict rules, so check local advice for your soil and climate.

• Driveway base: usually 4 to 8 inches, thicker if heavy vehicles will use it or the soil is soft.
• Walkway or garden path: about 3 to 4 inches of base, plus a thin top layer if you want a smooth surface.
• Patio or paver base: usually 4 to 6 inches, then a thin layer of bedding material.
• Under a shed or small slab: around 4 to 6 inches of clean stone.
• French drain or trench: often 8 to 12 inches or more, depending on the pipe and the depth of the trench.
• Decorative cover: 2 to 3 inches is enough for looks and weed control.

Why You Need Extra for Compaction and Waste

When you spread loose stone and then pack it down with a plate compactor, it gets denser and the layer gets thinner. If you only order the exact volume of the finished layer, you will come up short. For bases made from crusher run, an allowance of 10 to 20 percent is common. Clean stone does not compact as much, so 5 percent or less is often enough.

On top of that, a little stone is always lost. It spills, it mixes into the soil below, and uneven ground takes more than you planned. Adding about 5 percent for waste is a safe habit. If your ground is rough or you are filling a lot of low spots, go higher.

Running short is annoying and often costs more, because a second small delivery can come with its own fee. A small amount left over is easy to use somewhere else in the yard.

Crushed Stone Cost per Ton and per Cubic Yard

Prices change a lot from one area to another, and they depend on how far the quarry is from your site. In many parts of the US, common crushed stone often sells for somewhere between $25 and $60 per ton, and the cost per cubic yard is that price multiplied by the weight of a yard. Decorative stone and pea gravel cost more. Delivery is usually extra, and many suppliers charge a flat fee per load or by distance.

That is why the calculator lets you enter your own price and choose whether it is per ton or per cubic yard. It converts between the two for you, so you can compare quotes from different suppliers even if they price in different ways. The default numbers are only a starting point.

Remember that the stone is not the only cost. Geotextile fabric, edging, a plate compactor rental and labor can add up. Turn them on in the calculator to see the full picture, and use the contingency box to leave some room for surprises.

Bulk Delivery or Bagged Stone?

For anything bigger than a small garden path, bulk delivery is almost always cheaper. A dump truck brings the stone to your driveway, and you only pay for the weight and a delivery fee. A typical truck carries around 10 to 14 tons, so the calculator shows how many loads you need.

Bagged stone makes sense for tiny jobs, such as filling a small planter or a short stepping-stone path. A bag of half a cubic foot does not go far. You would need around 54 bags to make one cubic yard, which gets expensive and tiring very quickly. The calculator shows a bag count too, so you can see at a glance whether bags are realistic for your project.

Tips for Laying a Crushed Stone Base

Good prep matters more than most people expect. Start by removing grass, roots and soft soil, and shape the ground so water runs away from buildings. If the soil is soft or clay-heavy, lay geotextile fabric first. It keeps the stone from sinking into the soil and keeps the layers separate.

Spread the stone in layers and compact each one before adding the next. Do not make a layer much thicker than about 4 inches at a time, or the bottom will not pack down properly. Lightly dampening crusher run helps it bind. Finish by checking the surface with a long straight board and filling any low spots.

If you are building a path or patio, install edging before you finish the top layer. Edging holds the stone in place and keeps the edges from spreading over time.

Common Mistakes to Avoid

The most common mistake is forgetting compaction and ordering the exact volume. The second is using the wrong stone, for example clean stone as a driveway base where crusher run would pack better. Another mistake is skipping fabric on soft ground, which lets the stone slowly disappear into the soil.

People also mix up units. A cubic yard is not a ton, and square feet are not cubic feet. If a quote seems far off from your estimate, check that you are comparing the same unit. This calculator shows volume and weight side by side to help with that.

Finally, remember that this tool gives an estimate. Stone density, local prices and site conditions all vary, so confirm the final quantity and price with your supplier before you order.