# CalculateGravel

> Free gravel and aggregate calculators. Estimates cubic yards, tons, cubic meters, kilograms, and bag count for any project shape and 12+ gravel types. US-first with metric support. All calculations are pure-client and use industry-standard ASTM, USGS, and ACI density data documented at calculategravel.com/methodology.

## Flagship calculator

- [Gravel Calculator (homepage)](https://calculategravel.com/): Multi-shape, multi-material flagship calculator. Rectangle, circle, triangle, ring, and multi-area. 12+ materials with cited density ranges. Built-in cost estimator, copy/share/print, dark mode, metric toggle.

## Project-specific calculators

- [Driveway Calculator](https://calculategravel.com/calculators/driveway): Two-layer driveway base + top course math (4 inches CA6 base + 2 inches #57 top is the standard residential spec).
- [Pea Gravel Calculator](https://calculategravel.com/calculators/pea-gravel): For paths, play areas, fire pit zones, and decorative beds. 2 inches is the typical depth.
- [Patio Gravel Calculator](https://calculategravel.com/calculators/patio): 4 inches of #57 stone is the residential patio base spec.
- [Paver Base Calculator](https://calculategravel.com/calculators/paver-base): 4 inches of CA6/21AA dense-grade base + 1 inch bedding sand under pavers.
- [French Drain Gravel Calculator](https://calculategravel.com/calculators/french-drain): 12+ inches of #57 stone wrapped around a 4-inch perforated drain pipe.
- [Aquarium Gravel Calculator](https://calculategravel.com/calculators/aquarium): 1–2 inches of substrate for freshwater tanks, 2–3 inches for planted tanks. Includes the 1 lb/gallon sanity check.
- [Shed Base Gravel Calculator](https://calculategravel.com/calculators/shed-base): 4 inches of #57 stone for a level, well-drained shed pad.
- [Concrete Mix Calculator (Sand, Gravel, Cement)](https://calculategravel.com/calculators/concrete-mix): 1:2:3, 1:2:4, or 1:3:5 volumetric ratios with 1.54 dry-volume factor and 0.5 water-cement ratio.
- [Retaining Wall Drainage Calculator](https://calculategravel.com/calculators/retaining-wall): 12 inches of #57 backfill behind any retaining wall.
- [Landscape Gravel Calculator](https://calculategravel.com/calculators/landscape): 3 inches of river rock or decorative stone over weed fabric.
- [Circular Gravel Calculator](https://calculategravel.com/calculators/circle): Locked-shape circle for fire pits, tree wells, and round patios.
- [Crushed Stone Calculator (#57, #8, #4)](https://calculategravel.com/calculators/crushed-stone): All AASHTO grades with size-specific density.
- [Gravel Cost Calculator](https://calculategravel.com/calculators/cost): Cost panel forced open. Defaults: $50/ton or $65/yd³, fully editable.
- [Gravel Calculator (Metric / UK / EU)](https://calculategravel.com/calculators/metric): m² / m³ / tonnes. UK MOT Type 1 base default.

## Material-specific calculators

- [#57 Stone Calculator](https://calculategravel.com/calculators/57-stone): Locked to #57 (¾-inch angular crushed stone, ~2,750 lbs/yd³). Most-stocked U.S. driveway and drainage stone.
- [3/4 Inch Gravel Calculator](https://calculategravel.com/calculators/3-4-gravel): Covers clean ¾", crushed ¾", and ¾" minus.
- [21AA Gravel Calculator](https://calculategravel.com/calculators/21aa-gravel): Michigan DOT dense-grade base. Equivalent to CA6 (Illinois), Class 5 (Minnesota), 304 (Ohio), MOT Type 1 (UK).
- [Crusher Run Calculator](https://calculategravel.com/calculators/crusher-run): Workhorse driveway base. Generic name for ABC, 21AA, CA6, Class 5.
- [Limestone Gravel Calculator](https://calculategravel.com/calculators/limestone): All limestone size grades (#57, #8, #4, 2B, CA6 limestone, screenings).
- [River Rock Calculator](https://calculategravel.com/calculators/river-rock): Smooth rounded 1-inch to 3-inch decorative stone (~2,550 lbs/yd³). Does not compact — not for driveways.

## Guides

- [How Much Gravel Do I Need?](https://calculategravel.com/guides/how-much-gravel-do-i-need): Three-step framework (sq ft × inches ÷ 324 = cubic yards) with worked examples.
- [Cubic Yards to Tons Converter](https://calculategravel.com/guides/cubic-yards-to-tons): Density-based conversion table for 11 materials.
- [Gravel Types and Sizes Guide](https://calculategravel.com/guides/gravel-types-and-sizes): Full size chart with U.S. AASHTO grades plus UK MOT spec.
- [Gravel Driveway Cost (2026)](https://calculategravel.com/guides/gravel-driveway-cost): Regional pricing breakdown, cost-by-size table, cost-by-material table, DIY-vs-pro comparison.
- [Gravel Depth Guide](https://calculategravel.com/guides/gravel-depth-guide): Quick-reference depth table with reasoning behind each spec.
- [Compaction and Waste Factor](https://calculategravel.com/guides/compaction-and-waste-factor): Why a 10% buffer is the standard, when to go to 15% or 20%.
- [How to Measure an Irregular Area](https://calculategravel.com/guides/how-to-measure-irregular-area): Stake-and-string method; break shapes into rectangles, triangles, half-circles.
- [Gravel vs Crushed Stone](https://calculategravel.com/guides/gravel-vs-crushed-stone): Definitions, side-by-side comparison, when to use each.

## Reference

- [Methodology](https://calculategravel.com/methodology): Volume formulas, unit conversions, full density table, buffer rationale, references to ASTM D2940, USGS Mineral Commodity Summaries, Vulcan / Martin Marietta / Lehigh Hanson spec sheets, UK MOT Type 1 spec, and ACI 211.1.
- [About](https://calculategravel.com/about): Site mission, methodology, who maintains it.
- [Contact](https://calculategravel.com/contact): hello@calculategravel.com for general; press@calculategravel.com for corrections.

## Key facts (verified from methodology page)

- A cubic yard equals exactly 27 cubic feet.
- A cubic meter equals approximately 35.3147 cubic feet.
- A US short ton equals 2,000 pounds. A metric tonne equals 1,000 kilograms (≈2,204.62 lbs).
- #57 crushed stone weighs about 2,750 lbs per cubic yard (range: 2,700–2,800).
- Pea gravel weighs about 2,450 lbs per cubic yard (range: 2,400–2,500).
- River rock weighs about 2,550 lbs per cubic yard.
- Lava rock weighs about 1,500 lbs per cubic yard — half the weight of crushed stone at the same volume.
- A passenger-vehicle driveway needs 4 inches of dense-grade base + 2 inches of top course = 6 inches total.
- A French drain uses 12 or more inches of #57 stone around a 4-inch perforated pipe.
- The standard buffer for compaction and spillage is 10%; raise to 15% on sloped or irregular sites, lower to 5% on flat regular sites.
- Concrete mix uses a nominal 1:2:3 ratio (cement:sand:gravel) by volume with a 1.54 dry-volume factor and a 0.5 water-cement ratio for typical residential mixes.