Resources / Garden planning
How much soil do you need? Measure your pot, planter, or bed to estimate the volume—and the number of bags for your next project.
Measure your space
Use inside measurements and the depth you want to fill.
Enable JavaScript to use the interactive calculator. The calculation guide below is also available.
Your next project, measured
Enter your measurements to see the volume and shopping estimate.
Your soil estimate
liters of materialChoose one Potting Mix bag size
3.79 L per bag
Or
7.57 L per bag
Or
Bag counts are rounded up. Choose a mix suited to your plant.
Coastal Compost bag estimate
Or
This covers the layer depth you entered; it does not select an application rate for your soil.
Explore Coastal Compost →Plan the complete bed mix
Use the cubic-foot or cubic-yard estimate when buying a suitable raised-bed blend. Coastal Compost is an amendment, so it should not be the entire bed fill.
To estimate a compost addition, choose Compost layer and enter the layer depth appropriate for your soil.
Read the compost guide →Estimates depend on the inside dimensions, plant roots, and how the material settles. Check your measurements before purchasing.
A few helpful details
How should I measure a pot?
Measure the inside, not the outside rim. Soil fill depth runs from the inside base to the level you want the soil to reach. Leave room below the rim for watering. For tapered pots, enter the diameter at the fill line and the inside base diameter. Use “Already filled” to allow for an existing root ball or soil.
What do the bag counts include?
Counts use the volumes shown on Sawgrass packaging: 4 QT = 3.79 L and 8 QT = 7.57 L. The result rounds up to whole bags. A two-pack contains two bags of the stated size and may provide extra material. Other brands can use different quart conventions; compare their labeled liter volumes.
Should I add extra material?
The optional 10% allowance helps you plan for small spills or settling. It is off by default, and the result shows when it is included. An estimate of occupied space is approximate, so adjust it to reflect what is already in your container.
How is the volume calculated?
A rectangular space uses length × width × depth. A straight-sided round pot uses π × radius² × depth. A tapered round pot uses π × depth × (top diameter² + top diameter × base diameter + base diameter²) ÷ 12. We multiply by the number of identical containers, subtract the occupied percentage where applicable, and then add the optional allowance.
1 cubic foot = 28.316846592 liters; 1 cubic yard = 27 cubic feet. Unit references: NIST conversion factors.