Crushed Stone Calculator

About Crushed Stone Calculation

The Crushed Stone Calculator estimates volume in m³ and mass in tonnes from your site dimensions and layer thickness, then shows coverage per tonne and total cost. It works as a crushed rock calculator and stone estimator for bases, paths, patios, and driveways, including mixes with fines such as crusher run and stone dust.

Choose the dimension type (length × width, area, circle, or irregular shape), pick the aggregate fraction (per EN 13242) and origin, and set whether the thickness is specified before or after compaction. You can also set allowance for waste, moisture, density, and price per tonne or per m³.

Tips and Tricks

• Fractions and naming. Common European fractions are 4/8, 8/16, 16/32, 32/63, and blends with fines such as 0/31.5, 0/45, 0/63 (often called crusher run or crush-and-run). Stone dust is the finest portion of these blends.
• Metric alternative to “3/4”. For a “19 mm crushed stone calculator” scenario, select the 16/32 mm fraction. This size is widely used for sub-bases and drainage layers.
• Typical compacted thicknesses. Garden paths: 3-5 cm; patios and paving: 5-8 cm; light-duty driveways: 8-12 cm; heavy-duty sub-base: 12-20 cm. Add a separate bedding of stone dust only if your design specifies it.
• Compaction factor. When entering thickness before compaction, use a factor k. Aggregates often compact by k ≈ 1.10-1.30; the calculator converts to compacted thickness automatically.
• Density & moisture. Typical bulk density for crushed stone ranges from ~1 200 to 1 900 kg/m³ depending on fraction and origin. Moisture increases mass but not volume, which affects cost when priced per tonne.
• Allowance. A reserve of 5-15 % is common to cover trimming and uneven subgrade; adjust higher for complex shapes.

Examples above assume density ≈ 1.55 t/m³. Your results will vary with the selected fraction, origin, density, moisture and allowance.

FAQs

How much crushed stone do I need?

Enter the site dimensions, choose compacted thickness, select the fraction and origin, and the tool outputs volume in m³ and mass in t and kg. If you only know the loose thickness, switch to “Before compaction” and set the compaction factor to convert it.

How do I estimate crusher run?

Select a blend with fines such as 0/31.5 or 0/45 mm. These compact well for sub-bases. Keep an allowance of 10-15 % and check that the compacted thickness meets your design.

What density should I use in the calculator?

For clean aggregates, 1 400-1 700 kg/m³ is common; blends with fines can reach 1 700-1 900 kg/m³. You can override the prefilled value if you have a supplier's test sheet for the exact material.

How do I use the calculator for 19 mm stone?

Choose the 16/32 mm fraction (the usual 19 mm category), set the compacted thickness for your application, and the calculator will provide m³, tonnes, kilograms, and coverage per tonne.

Can I estimate by cost instead of tonnes?

Yes. Select whether your price is per tonne or per m³ and enter the amount. The calculator automatically computes total cost using your chosen density and moisture settings.