Base Rock Tonnage Calculator
Convert paved or graded area and compacted thickness into tons of aggregate base. Density defaults to 125 lb/ft³, a common compacted crushed-rock value, and can be changed to match the quarry or mix sheet.
Enter your values, then press Calculate.
How to calculate
Enter the area and compacted thickness of the base rock layer. Use the supplier density when you have it. The calculator converts thickness to feet, finds cubic feet, multiplies by density, then divides by 2,000 pounds per ton.
Formula
Volume (ft³) = area (ft²) × thickness (ft). Weight (lb) = volume × density (lb/ft³). Tons = weight ÷ 2,000. Waste multiplies the neat tonnage. Cubic yards = ft³ ÷ 27.
Common use cases
- Driveway and parking-lot base
- Road aggregate base course
- Pad and sidewalk base
- Comparing 4 in vs 6 in sections
Assumptions
- Thickness is compacted aggregate thickness, not the loose lift dumped from the truck.
- Default 125 lb/ft³ is a common crushed-stone starting point, not a quarry ticket.
- Area is the plan footprint of the base, including shoulders only if you measured them.
- Waste covers irregular subgrade and over-spread, not a change from bank to loose.
Limitations
- This is not the hot-mix calculator. Do not leave 145 lb/ft³ in the density field for aggregate.
- Does not convert bank borrow to compacted base. Use shrink/swell if the pit quotes bank yards.
- Does not size the section (6 in vs 8 in) or pick gradation (3/4 in minus vs Class 2).
- Moisture and truck heaping change delivered tons; tickets beat this estimate.
Worked examples
1000 sf at 6 inches and 125 pcf
1,000 sf of 6 in compacted crushed base at 125 lb/ft³ is a typical residential driveway section before you add waste for the flare at the street.
1. Volume in cubic feet
1,000 ft² × 0.5 ft = 500 ft³
2. Convert to cubic yards
500 ft³ ÷ 27 = 18.5185 yd³
3. Weight in tons
500 ft³ × 125 lb/ft³ ÷ 2,000 = 31.25 tons
10% waste increases the order quantity only
1. Volume in cubic feet
1,000 ft² × 0.5 ft = 500 ft³
2. Convert to cubic yards
500 ft³ ÷ 27 = 18.5185 yd³
3. Weight in tons
500 ft³ × 125 lb/ft³ ÷ 2,000 = 31.25 tons
Crushed base, not hot-mix asphalt
The prism is the same idea as asphalt tonnage — area × compacted thickness × density ÷ 2,000 — but the default density is crushed aggregate (often 125 lb/ft³), not compacted HMA (often 145 lb/ft³). Do not order base with the asphalt calculator or millings with either default. Compacted thickness is the specified lift after rolling, not the loose lift.
Density and coverage
At 125 lb/ft³, one cubic yard is 27 × 125 ÷ 2,000 = 1.6875 tons. A 1,000 sf area 6 in thick is 31.25 tons before waste (the bundled example). Use the quarry ticket or lab density when you have it. Unusual densities (the 90 pcf warning) are a prompt to confirm the material, not a recommendation.
Quarry tons versus compacted thickness
A 1,000 sf driveway at 6 in compacted and 125 lb/ft³ is 3.125 neat tons per 100 sf, or 31.25 tons before waste. If the quarry sells by the ton and you think in cubic yards, 125 lb/ft³ is 1.69 tons per cubic yard compacted (125 × 27 ÷ 2,000). Recycled concrete and ballast can sit well above or below 125 — type the ticket density instead of arguing with the default.
Related calculators
- Asphalt Tonnage CalculatorEstimate hot-mix asphalt tons from area, thickness, and density.
- Paving Area CalculatorConvert pavement length and width into square feet and square yards.
- Trench Excavation CalculatorConvert trench length, width, and depth into cubic yards of excavation.
- Bedding CalculatorEstimate pipe bedding cubic yards from length, width, and depth.
FAQ
What density should I use for crushed base?
Compacted crushed rock is often 120–140 lb/ft³. 125 lb/ft³ is a common estimating default. Use the quarry ticket when you have it.
How many tons per cubic yard?
At 125 lb/ft³, one cubic yard is about 1.69 tons (27 × 125 ÷ 2,000).
Is 125 lb/ft³ the same as 145 for asphalt?
No. 145 lb/ft³ is a common compacted hot-mix default. 125 lb/ft³ is a common crushed-base starting point. Using the asphalt default on rock overstates tons.
How do I get truckloads of base?
Convert tons to cubic yards with the density you used, then open the truckload estimator with the truck size on the job. This page stops at tons.
Disclaimer
These calculators are estimating tools for planning and field checks. They are not a substitute for approved plans, specifications, licensed professional engineering, or governing standards. Confirm densities, waste factors, and yields with your supplier and project documents.