Estimate how much potting soil or potting mix you need for containers, flower pots, planters, hanging baskets, grow bags, and raised planters. Calculate cubic feet, quarts, gallons, liters, bags needed, and estimated potting soil cost.
Round pot mode:
The calculator uses pot diameter and fill height to estimate the volume of potting soil needed.
Rectangular planter mode:
The calculator multiplies length, width, and fill height to estimate planter soil volume.
Square planter mode:
The calculator uses the length value as both length and width for a square planter.
Known volume mode:
The calculator converts a known container volume from quarts, gallons, liters, or cubic feet into the other common units.
A potting soil calculator helps estimate how much potting mix to buy before filling containers, pots, planters, grow bags, hanging baskets, and raised planter boxes.
It can help compare bag sizes, estimate total cost, convert between cubic feet and quarts, and avoid buying too little or too much potting soil.
Your result shows the estimated potting soil needed in cubic feet, quarts, gallons, and liters. It also shows the number of bags needed, estimated cost, volume per container, extra material allowance, and settling or shrinkage allowance.
Use the pot diameter to find the radius, then multiply π by radius squared and by the fill height. Convert cubic inches to cubic feet by dividing by 1,728.
One cubic foot is about 29.92 quarts. Many potting soil bags are labeled in either cubic feet or quarts.
One cubic foot is about 7.48 gallons. Grow bags and large containers are often listed in gallons.
Yes. Adding 5% to 15% extra can help account for settling, spills, filling gaps, and topping off containers after watering.
No. This is an estimate. Actual potting soil needs can vary based on container shape, tapering sides, drainage space, root ball size, soil settling, and how full you fill the container.