StoneRock Coverage Calculator

Rock Coverage Calculator

Calculate how much area your landscape rock will cover—or determine how many tons you need. Get accurate coverage estimates that prevent costly over-ordering.

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Coverage Per Ton

Rock Type2" Depth3" Depth4" Depth
Pea Gravel (3/8")80 sq ft55 sq ft40 sq ft
Crushed Stone (3/4")90 sq ft60 sq ft45 sq ft
River Rock (1-2")100 sq ft65 sq ft50 sq ft
River Rock (2-4")110 sq ft75 sq ft55 sq ft
Lava Rock180 sq ft120 sq ft90 sq ft

Expert Contributors

Why expert review matters

Every calculator is reviewed by certified professionals to ensure accuracy.Hawkin's CCP, CEP certification ensures professional-grade precision.

Pro Tips

  • Match depth to purpose: 2" for decorative beds, 3-4" for weed suppression, and 4-6" for drainage applications
  • Larger rock sizes (3-6") require less depth and cover 20-30% more area per ton than small stone
  • Install steel or aluminum edging before spreading rock to contain material and maintain clean lines
  • Order 5-10% extra for irregular shapes and settling—rock doesn't decompose so extra becomes repair material

Common Questions

How much rock per square foot?

12-15 lbs at 2" depth, 18-22 lbs at 3" depth

How many sq ft does a ton cover?

80-120 sq ft at 2" depth depending on rock size

Best depth for weed prevention?

3-4 inches over landscape fabric

Bulk vs bags—which is cheaper?

Bulk is $25-75/ton; bags equal $300-600/ton

How the Calculator Works

This calculator uses the formula: Coverage = (Tons × 2000) ÷ (Depth × Density), where density varies by rock type from 50-105 lbs per cubic foot. For tonnage calculations, we reverse the formula and apply your selected waste factor. All estimates account for natural void space between stones.

Formula

Tons = (Area × Depth ÷ 12 × Density) ÷ 2000

Area Covered = (Tons × 2000) ÷ (Density × Depth ÷ 12)

Quick Reference

Decorative depth
2"
Weed suppression
3-4"
Drainage areas
4-6"
Lava rock weight
50 lb/cu ft
River rock weight
85-90 lb/cu ft