Mulch, Soil & Gravel Calculator

Welcome to the Mulch, Soil & Gravel Calculator, your comprehensive tool for estimating landscaping material quantities. Whether you are planning a garden bed, raised planter, driveway, or playground, this calculator helps you determine exactly how much mulch, topsoil, gravel, or sand you need, along with weight estimates for delivery and bag counts for store purchases.

How to Use This Calculator

1. Select your material type - Choose from mulch (bark chips), topsoil (compost), gravel (crushed stone), or sand based on your project needs.
2. Choose your measurement system - Select US Customary (feet, inches) or Metric (meters, centimeters).
3. Select area shape - Choose rectangle for most projects, or circle/triangle for curved beds and irregular areas.
4. Enter dimensions - Input your length, width (or radius/base/height), and desired material depth.
5. Add waste factor - Include 10-15% extra for settling, spillage, and uneven terrain.
6. Calculate - Get instant results including volume, weight, bag counts, and truck load estimates.

Recommended Material Depths

Understanding Cubic Yards

A cubic yard is the standard unit for bulk landscaping materials in the United States. It equals a cube measuring 3 feet on each side (3 ft × 3 ft × 3 ft = 27 cubic feet). Most landscape supply companies sell materials by the cubic yard for bulk delivery.

Quick Reference

• 1 cubic yard = 27 cubic feet
• 1 cubic yard = 0.765 cubic meters
• 1 cubic yard of mulch covers approximately 160 sq ft at 2 inches deep
• 1 cubic yard of gravel weighs approximately 2,700 lbs (1.35 tons)

Material Weight Reference

Bagged vs. Bulk Materials

For small projects under 3 cubic yards, bagged materials from home improvement stores may be convenient. For larger projects, bulk delivery is typically more economical.

Bagged Material Sizes

• Mulch: Typically 2 cubic feet per bag (13-14 bags per cubic yard)
• Topsoil: Typically 1 cubic foot per bag or 40 liters
• Gravel/Sand: Typically 0.5 cubic feet or 50 lb bags

Why Add a Waste Factor?

Adding 10-15% extra material accounts for:

• Settling and compaction - Materials settle over time, especially gravel
• Spillage - Material lost during transport and spreading
• Uneven terrain - Low spots requiring more material
• Measurement variations - Areas are rarely perfectly flat or rectangular

Frequently Asked Questions

How many cubic yards of mulch do I need?

To calculate cubic yards of mulch: multiply the length (ft) × width (ft) × depth (in), then divide by 324. For example, a 10×20 ft area with 3 inches of mulch needs: 10 × 20 × 3 ÷ 324 = 1.85 cubic yards. Add 10% extra for settling and uneven coverage.

How much does a cubic yard of gravel weigh?

A cubic yard of gravel typically weighs between 2,400-2,900 pounds (1,100-1,300 kg), depending on the type and moisture content. Pea gravel is lighter at around 2,400 lbs, while crushed stone can weigh up to 2,900 lbs per cubic yard.

How deep should mulch be?

Mulch should be applied 2-4 inches deep for most garden beds. For weed suppression, 3-4 inches is ideal. Avoid piling mulch against plant stems or tree trunks (volcano mulching), as this can cause rot and pest problems.

How many bags of mulch are in a cubic yard?

One cubic yard equals 27 cubic feet. With standard 2 cubic foot bags, you need about 13-14 bags per cubic yard. Bagged mulch is convenient for small projects, but bulk delivery is more economical for projects requiring more than 3-4 cubic yards.

Should I add extra material for waste?

Yes, add 10-15% extra material to account for settling, compaction, spillage, and uneven terrain. For gravel driveways that will be compacted, add 15-20% extra. This waste factor ensures you have enough material to complete the job properly.