Estimate how much soil or potting mix you need for containers, planters, grow bags, pots, window boxes, and raised containers. Calculate cubic feet, quarts, gallons, liters, bags needed, and estimated container soil cost.
Round container mode:
The calculator uses diameter and fill depth to estimate container soil volume.
Rectangular container mode:
The calculator multiplies length, width, and fill depth to estimate soil for planter boxes and rectangular containers.
Square container mode:
The calculator uses the length value as both length and width for square containers.
Known volume mode:
The calculator converts a known container size from quarts, gallons, liters, or cubic feet into the amount of soil needed.
A container soil calculator helps estimate how much soil or potting mix to buy before filling pots, grow bags, planter boxes, window boxes, and patio containers.
It can help compare bag sizes, convert container volume units, estimate total cost, and reduce the chance of buying too little or too much soil.
Your result shows estimated container soil needed in cubic feet, quarts, gallons, and liters. It also shows bag count, estimated cost, volume per container, total adjusted volume, drainage space reduction, root ball space, extra material, and settling allowance.
For a round container, multiply π by radius squared and fill depth. For a rectangular container, multiply length by width by fill depth. Then convert cubic inches to cubic feet by dividing by 1,728.
One cubic foot is about 29.92 quarts. This is useful because many container soil bags and pot sizes use different volume units.
One cubic foot is about 7.48 gallons. Grow bags and large containers are often listed in gallons.
Yes, if you are transplanting a large plant with an existing root ball. The root ball takes up space inside the container, so less new soil may be needed.
No. This is an estimate. Actual soil needs can vary based on container shape, tapered sides, drainage material, root ball size, soil settling, and how full the container is filled.