Construction calculator

Free gravel calculator

Enter your project's length, width, and depth — this gravel calculator returns cubic yards and tons of crushed stone needed using a 1.4 ton/yd³ bulk density, updated live, as you type.

InputsLive
Length
ft
Width
ft
Depth
in
Driveway: 4–6 in. Path/base: 2–4 in.
Result
Gravel needed
3.46 tons
2.47 yd³ · 66.7 ft³
Tons3.46
Cubic yards2.47
Cubic feet66.7
Density used1.4 ton/yd³

Density assumed at 1.4 ton/yd³. Actual varies by stone type. Add 10% overage when ordering.

Results are estimates. Consult a professional.

How it's calculated

How the gravel calculator works

The calculator converts your project's length, width, and depth into cubic feet, then into cubic yards — the unit gravel suppliers use for pricing. Multiplying by the material's density gives the weight in tons. A 10–15% settling allowance is built in because gravel compacts and migrates after delivery, and a light underestimate means a return trip to the quarry.

volume (ft³) = length (ft) × width (ft) × (depth (in) ÷ 12)
volume (yd³) = ft³ ÷ 27
tons (base) = yd³ × density factor
tons (total) = tons × 1.10 to 1.15 ← settling allowance
Typical density factors:
pea gravel (3/8 in) → 1.2 ton/yd³
3/4-in crushed stone → 1.4 ton/yd³
dense-grade base / crusher run → 1.5 ton/yd³
Engineering ToolBox — bulk density of crushed stone, gravel, and aggregate materials.
Example

Worked example: 500 sq ft gravel driveway at 4-inch depth

Example: 20 × 25 ft driveway resurfaced with 3/4-in crushed stone

Sarah is refreshing a 20 ft × 25 ft gravel driveway with 4 inches of 3/4-inch crushed stone (density 1.4 ton/yd³). She adds a 10% settling buffer to her order.

ft³ = 20 × 25 × (4 ÷ 12) = 166.7 ft³
yd³ = 166.7 ÷ 27 = 6.17 yd³
tons (base) = 6.17 × 1.4 = 8.64 tons
tons (+10%) = 8.64 × 1.10 = 9.50 tons
≈ 9.5 tons
Sarah should order 10 tons of 3/4-inch crushed stone to cover the 500 sq ft driveway at 4-inch depth with a settling allowance. A standard delivery truck carries 10–14 tons.
Quick reference

Gravel tonnage for common project areas

All figures use 3/4-inch crushed stone density (1.4 ton/yd³) and include a 10% settling allowance. For pea gravel, multiply by 0.86; for dense-grade base, multiply by 1.07.

Project area2-in depth (tons)4-in depth (tons)6-in depth (tons)
100 ft²0.951.902.85
200 ft²1.903.805.70
500 ft²4.769.5014.26
1,000 ft²9.5019.0128.52
2,000 ft²19.0138.0257.04

Based on 3/4-in crushed stone at 1.4 ton/yd³ + 10% settling buffer. Source: Engineering ToolBox bulk density data.

Practical tips

Tips for buying and placing gravel

Choosing the right gravel type and depth for the application makes a larger difference than most homeowners expect — the wrong material in the wrong layer washes out, sinks, or shifts within a season.

  • Layer your driveway correctly — a properly built gravel driveway uses three layers: 4–6 in of large base rock (3–4 in crushed stone) at the bottom, 4 in of dense-grade base (crusher run) in the middle, and 2–3 in of finish gravel (pea gravel or 3/4-in crushed stone) on top. Skipping the base layers leads to rutting.
  • Match gravel type to the application — 3/4-in crushed stone is the all-purpose workhorse for driveways and paths. Pea gravel is soft underfoot but migrates easily; use edging to contain it. Dense-grade base compacts firm and is ideal for sub-base layers. French drains need washed, rounded stone (no fines) to allow drainage.
  • Order in tons, not bags — bulk delivery from a local quarry costs 50–70% less per ton than bagged stone from a home-improvement store. Most quarries have a 3-ton minimum delivery; anything smaller may be cheaper to pick up in a pickup truck.
  • Add edging before you spread — plastic, steel, or stone edging installed before gravel is placed saves significant material. Without containment, gravel spreads into lawn and flower beds within one season, especially on sloped sites.
  • Plan for drainage — gravel is permeable, which is one of its advantages over asphalt. Avoid compacting gravel so tightly that fines fill all the voids; this defeats the drainage benefit and turns the surface hard rather than forgiving underfoot.
Accuracy & limits

Accuracy and limitations

The formula is geometrically exact for the dimensions entered. The main variable is density: the 1.4 ton/yd³ factor is a reliable industry standard for 3/4-inch crushed stone, but density varies by aggregate type, moisture content, and particle gradation. Wet gravel is heavier than dry; rounded pea gravel is lighter than angular crushed stone. If your supplier provides a density spec, use that figure instead of the default.

This calculator assumes a flat, rectangular area. For sloped or irregular sites, break the project into rectangular sections and sum the results. Add extra material for high-traffic areas, steep slopes (gravel migrates downhill), or sites prone to frost heave. Always confirm tonnage with your supplier before ordering — they can verify local material weights and delivery minimums.

Glossary

Gravel and aggregate terms defined

The standard volume unit used by gravel and aggregate suppliers. One cubic yard equals 27 cubic feet, or a cube roughly 3 ft × 3 ft × 3 ft. Pricing is almost always quoted per cubic yard or per ton.
Angular aggregate produced by mechanically crushing quarried rock. The sharp edges interlock when compacted, making crushed stone more stable than rounded gravel for driveways and sub-base applications. Common sizes: 3/4 in, 1.5 in (ballast), 2.5 in.
Small, rounded, smooth aggregate (3/8 in diameter) produced by screening river or quarry stone. Comfortable underfoot and visually attractive; density approximately 1.2 ton/yd³. Requires edging to prevent spreading.
A blend of crushed stone particles ranging from coarse to fine (including stone dust). Compacts into a firm, stable surface ideal for sub-base layers under asphalt or concrete, and as a stand-alone driveway material. Density approximately 1.5 ton/yd³.
Extra material ordered to account for volume loss from compaction, migration, and the natural settling of loose aggregate. Industry standard is 10–15% over the calculated volume.
A sub-surface drainage channel filled with washed, rounded aggregate (no fines) and a perforated pipe. The aggregate must be free-draining, so pea gravel or washed #57 stone (1 in) is used instead of dense-grade base.
The weight of loose material per unit volume. Gravel bulk density varies by particle shape, size, and moisture — typically 1.2–1.5 ton/yd³ for common construction aggregates.
About

About this gravel calculator

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Questions

Frequently asked questions about the free gravel calculator

A gravel calculator is a free online tool that helps you estimate tons of gravel needed for a driveway, walkway, or drainage layer. Gravel is sold by the ton. Standard density is ~1.4 ton/yd³ for dry, compacted aggregate. It runs entirely in your browser with instant results and no sign-up.
Crushed stone (#57 or 3/4-in minus) with crusher fines for binding. Lay 4 in over geotextile fabric on a graded base.
Asphalt has bitumen binder filling the voids. Gravel has only air gaps between stones, so its bulk density is lower.
For drainage / decorative use, no. For driveways or walkways, yes — at minimum 4 in of compacted base course (larger aggregate) topped with finer gravel.

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