How to Figure Cubic Yardage for Topsoil

After carefully laying layers of nutrient-rich soil and compost and planting your flowers, vegetables or other plants, you should put down a layer of topsoil to protect the quality, and sometimes expensive, soils underneath. Topsoil types range from very sandy to very clay. No matter the type, all topsoil types are packaged and sold by volume. You need to calculate how many cubic yards you need before purchasing topsoil.

Things You'll Need

• Ruler

Instructions

1. Decide how deep you need your topsoil to be. If there has been significant erosion in your bed, you will need 4 to 6 inches of topsoil. If you are adding a top layer of compost, you might need less than 4 inches. Take into consideration the depth of your bed if you are planting in a raised bed. Measure how deep your topsoil needs to be to reach near the top of the bed.

2. Measure the size of the garden or flower bed into which you need to apply topsoil. Measure the length and width by inches.

3. Multiply the length times the width, in inches, of your areas.

4. If you have more than one garden or flower bed, add the results from the calculations for all of them.

5. Take the sum of all the areas and divide it by 36, the number of inches in a yard.

6. Multiply this number by the number of inches deep you want your bed.

7. This is the number of cubic yards of topsoil you need.

References

• University of Georgia: Soil Preparation
• University of Missouri Extension: Caring for Flooded Lawns
• Washington State University Cooperative Extension: Math for Gardeners