Soil Amendment Calculator

1. Choose your measurement method. Enter the total area in square feet, or enter length and width separately for rectangular beds.

2. Select your material type. Different materials have different densities, which affects weight and hauling requirements. The calculator adjusts the weight estimate automatically.

3. Select your depth. Use 2-3 inches for amending existing beds, 4-6 inches for building new beds from scratch, and 3-4 inches for gravel drainage layers.

4. Enter material cost (optional). Enter the bulk price per cubic yard from your supplier to get a total material cost estimate.

The calculator uses the standard cubic volume formula used across the landscaping industry:

Material densities vary significantly. One cubic yard of topsoil weighs about 2,800 lbs (1.4 tons), while the same volume of sand weighs 3,200 lbs (1.6 tons). Knowing the weight is critical for planning truck loads and ensuring your delivery vehicle can handle the material.

Bag count is calculated at 2 cubic feet per bag (standard retail bag). For jobs over 3 cubic yards, bulk delivery is significantly more cost-effective than buying bags.

New bed construction. Calculate exactly how much topsoil or garden mix you need to build beds from scratch. Avoid over-ordering and paying for material you do not need, or under-ordering and making a second trip to the supplier.

Gravel and drainage projects. Whether it is a French drain, patio base, or driveway, get the exact cubic yards of gravel or stone needed. The weight estimate helps you plan dump truck loads.

Compost and amendment applications. For annual bed amendments, top-dressing, or soil improvement projects, calculate the exact volume needed at the recommended depth for the application.