YardCompost Calculator: Yards, Bags & Cost
Use this compost calculator to answer “How much compost do I need?” for a lawn or garden in cubic yards and bags. Enter your application depth and compare bagged and bulk costs.
01 Measure your space
Add each bed or section. Different sizes are welcome.
Extra is an ordering allowance, not a recommendation to apply a thicker layer.
Enable JavaScript for an interactive estimate. Formulas and examples are available below.
02 Compare your prices
OPTIONALReplace example prices with your store and supplier quotes.
Minimum and increment use the selected bulk pricing unit. Prices exclude tax and installation.
Take it to the store
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Finished compost for a lawn or garden
This calculator estimates the volume of finished compost spread over an area. It does not calculate the brown-to-green ratio for a compost pile. Choose a depth appropriate for your project and local guidance; a lawn topdressing and a new garden bed need different treatment.
Use “Known area” if you know your lawn’s square footage. For unevenly shaped spaces, calculate several sections. Keep existing paths, patios and unplanted areas out of the total.
Example: a thin layer over 1,000 sq ft
A quarter-inch layer over 1,000 square feet equals about 20.83 cubic feet, or 0.77 cubic yards, without an extra allowance. If each bag holds 1 cubic foot, purchase 21 whole bags. This example illustrates volume and is not an application recommendation.
Small depth changes have a large effect over a lawn. Doubling the layer from a quarter-inch to a half-inch doubles the material required. Check the intended application before increasing the quantity.
Frequently asked questions
Does this tell me how much compost my soil needs?
No. It turns an application depth into a quantity. Soil condition, the compost product and your plants determine the appropriate application.
Is this a compost recipe calculator?
No. It estimates finished compost to buy or apply. It does not estimate composting time, feedstock ratios or nutrient content.
Can I use compost as part of raised-bed fill?
Use the raised-bed soil calculator to divide the required new volume into a compost share and another fill component. Choose the blend using guidance appropriate to your bed.
How the estimate works
For each rectangular area, multiply length by width, then multiply by depth in feet. A square uses side length × side length. An oval uses length × width × π ÷ 4. A circle uses π × radius². Add the volumes of all areas, then apply the extra-material percentage once.
There are 27 cubic feet in one cubic yard. Bag quantities round up to whole bags. Bulk orders round up to the increment you enter, after applying your supplier’s minimum order. Taxes, installation, pickup costs and additional fees are excluded.