Skip to main content
Book Consultation →
Home projects100% FreeInstant

Gravel, Mulch and Topsoil Calculator: Volume and Bags

This free calculator finds how much gravel, mulch, topsoil, sand or compost you need for a path, bed or driveway. It gives the volume, the weight in tonnes and the number of bags.

By Debmedia Technologies LLP · Kolkata, India · Updated

What Is It and When Do You Need It?

Ordering loose materials means converting an area and depth into volume and weight. Suppliers sell by the tonne or the cubic metre, and garden centres sell by the bag.

Choose the material and enter the area and depth.

How to Use This Tool

  1. Choose the material.
  2. Enter the length, width and depth.
  3. Choose how it is sold.
  4. Press Calculate.

How the Calculation Works

Volume = length × width × depth ÷ 100 in cubic metres. Weight = volume × density, using typical densities in tonnes per cubic metre. Bags are the volume divided by the bag size (for example 40 litres = 0.04 m³) or the weight divided by 25 kg, rounded up. A 10 percent allowance is shown as well.

Worked Example

A path of 10 m by 2 m covered with 5 cm of gravel is 1 m³, weighing about 1.6 tonnes, or 64 bags of 25 kg. With 10% extra, 1.1 m³ and 1.76 tonnes.

Common Uses

  • Paths and driveways.
  • Garden beds and borders.
  • Under sheds and patios.
  • Ordering a delivery.

Tips and Common Mistakes

  • Order by weight for gravel and by volume for mulch.
  • Use a weed membrane under gravel.
  • Wet material is heavier than dry.

Next, you may need the flooring calculator, staircase calculator, recipe scaler, cups to grams converter.

Everything runs in your browser. Nothing you type is uploaded, stored or sent to any outside service.

Frequently Asked Questions

About 5 cm for paths, 7 to 10 cm for driveways and 10 cm or more for a base layer. Mulch is usually 5 to 7 cm deep.
It depends on the material and moisture. Gravel is about 1.5 to 1.7 tonnes, topsoil about 1.3 to 1.5 and dry bark mulch about 0.3 to 0.4.
Yes. Add 5 to 10 percent for settling and uneven ground.
This tool uses metres and centimetres. Convert first, 1 foot is 0.3048 m.

Disclaimer: results are calculated in your browser from the numbers you enter. Check important results before you rely on them for money, health, safety or legal decisions.