Gravel Calculator
Enter area and depth to get gravel, sand, or crushed stone volume, weight, and bag counts — with compaction allowance.
Material needed
- Density
- 1.5 t/m³
- 25kg bags
- 144
- 1-ton bags
- 4
Area × depth = volume, × density = weight. Compaction reduces volume, so order includes an allowance (usually 20%). Density varies by material and moisture.
What this tool does
The gravel calculator computes the volume (m³) and weight (tons) of gravel, sand, or crushed stone from area and depth. It applies per-material unit weights, includes a compaction allowance, and tells you the number of 25kg bags and 1-ton bulk bags to order. Use it for driveways, parking, drainage layers, and landscaping.
Who uses this
- Estimate gravel for yard/driveway paving
- Aggregate for drainage and base layers
- Landscaping gravel/decomposed-granite order
- Crushed-stone base before concrete
- Garden sand/gravel purchase amount
How to use
- 1Enter the area (m²) to cover, computed as length × width.
- 2Enter depth (cm). Gravel paving 5-10cm, compacted base 10-20cm is typical.
- 3Select material and compaction allowance (usually 20%) to see volume, weight, and bag counts.
Volume & weight formula
Volume (m³) = area (m²) × depth (m) Order volume = volume × (1 + compaction) Weight (tons) = order volume × unit weight Unit weight (t/m³, loose): gravel 1.5, sand 1.6, crushed 1.5, soil 1.4, mixed 1.55 25kg bags = weight(kg) / 25 1-ton bulk bags = ceil(weight in tons)
Real examples
Example 1: Yard 20m² × 10cm gravel
Volume 2m³, +20% compaction → 2.4m³. Weight 2.4 × 1.5 = 3.6 tons. 144 25kg bags or 4 bulk bags.
Example 2: Driveway drainage 30m² × 15cm crushed
Volume 4.5m³ × 1.2 = 5.4m³. Crushed 1.5 → 8.1 tons. Compacted bases need to be laid thicker.
Example 3: Garden sand 10m² × 5cm
Volume 0.5m³ × 1.2 = 0.6m³. Sand 1.6 → 0.96 tons. About 39 bags.
Frequently asked questions
Why a compaction allowance?+
Gravel/aggregate loses ~20-30% volume when compacted. To reach the target depth after compaction, you must order extra, so a compaction allowance (default 20%) is added.
How is unit weight determined?+
It varies by material and moisture. This tool uses general loose-dry values (gravel 1.5, sand 1.6 t/m³). Wet sand is heavier and may differ from the estimate.
Bags or bulk bags?+
Small amounts (under 1 ton) are easy in 25kg bags; large amounts are cheaper per unit in 1-ton bulk bags. The tool shows both — choose based on transport and storage.
What depth is right for gravel?+
Decorative finish 3-5cm, walkways 5-8cm, vehicle driveways 8-10cm, compacted base 10-20cm. Heavier loads need thicker layers.
Rubble vs crushed stone?+
Rubble is broken natural stone (uneven sizes); crushed stone is aggregate crushed to a set size. Bases mix rubble + crushed; finishes use uniform crushed/gravel.
Is geotextile separate?+
Yes. Weed-barrier/separation geotextile under gravel is calculated by area (m²) separately. This tool computes aggregate only.
Cautions
- •Unit weights are loose-dry general values — vary with moisture.
- •20% compaction is the default; adjust for compaction strength.
- •Wet sand/aggregate is heavier.
- •Geotextile and edging are separate.
- •Verify unit weight with the supplier for accurate ordering.
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Last reviewed: 2026-05-30