Gravel paths and driveways are sold by the bag at hardware stores and by the cubic metre from quarries.
About this calculator
Gravel paths and driveways are sold by the bag at hardware stores and by the cubic metre from quarries. Without a volume estimate you either short the base layer or pay for a truck you did not need.
This gravel calculator takes bed length and width, depth in centimetres, material density (crushed stone is roughly 1600 kg/m³), bag weight from the shelf label, wastage, and optional price per bag. It returns cubic metres, total kilograms with buffer, whole bags to buy, and material cost.
Compact in 5 cm lifts with a plate compactor on driveways. Paths can often sit at 5 cm over landscape fabric. Large projects above roughly 10 m³ may be cheaper with bulk delivery — compare the cubic-metre result here against quarry quotes. Use the [[volume]] calculator for odd shapes, the [[square-footage]] tool to verify area, and [[concrete]] when you are pouring a slab beneath the gravel base.
Common uses
- Sizing bagged gravel for a garden path or patio base
- Estimating crushed stone for a driveway extension
- Comparing bag cost against bulk cubic-metre delivery
- Planning drainage layer depth behind a retaining wall
- Quick material list for a landscaping quote
Frequently asked questions
How deep should gravel be for a driveway?
Build 10–15 cm of crushed stone over a compacted sub-base on soft soil. Light foot paths work with 5 cm. Heavy vehicles need thicker layers and edge restraint.
What density should I use?
Crushed aggregate and road base ≈ 1600 kg/m³. Pea gravel and decorative stone ≈ 1500 kg/m³. Very dense limestone can reach 1800 kg/m³ — check your supplier spec sheet.
How many 20 kg bags in a cubic metre?
At 1600 kg/m³, one m³ weighs about 1600 kg — roughly 80 bags of 20 kg before wastage. Bulk delivery usually wins above 5–10 m³.
Do I need a wastage buffer?
Add 10% for uneven ground and spillage. Steep or irregular beds may need 15%. Rake to level before compacting rather than over-ordering deeply.
Can I use this for other aggregates?
Yes. Enter the same area and depth with the correct density for sand, ballast or crusher dust. Only the density and bag size change.