Stone Calculator
Your estimate
Stone needed1.3 yd³35 ft³ · 0.99 m³
- Weight
- 1.75 tons3,496 lb · 1.59 t
- Estimated cost
- $140
Decorative rock for beds and borders, or flagstone for a patio or path.
Updated 2026-10-20 · Based on: supplier bulk densities (gravel ≈ 1.4 tons per yd³).
How to use the Stone Calculator
- Pick rectangle, circle or flagstone.
- Enter the bed size and depth (2–3 in for decorative rock).
- Choose the stone — lava rock is very light, river rock heavy.
- Read yards and tons.
Formula
Bulk stone: tons = area × depth × weight per volume.
Flagstone: one ton of 1–1½ in stone covers about 100 ft²; 2–2½ in stone about 70 ft².
Worked example
With the values preset in the calculator above: (Rectangle)
- Length
- 20 ft
- Width
- 10 ft
- Thickness
- 2 in
- Material
- Landscape rock
- Extra for waste
- 5 %
- Stone needed
- 1.3 yd³ (35 ft³)
- Weight
- 1.75 tons (3,496 lb)
- Estimated cost
- $140
Frequently asked questions
How much landscape rock do I need?
A 20 × 10 ft bed at 2 in deep takes 1.3 yd³ (35 ft³) — about 1.75 tons.
How much flagstone for a patio?
A 20 × 10 ft patio of 1–1½ in flagstone takes about 2.1 tons with 5 % extra.
How deep should decorative rock be?
2 in for small stone, 3 in for 1–2 in river rock, over landscape fabric.
More calculators
Estimates only — check quantities with your supplier and local building code before you order.