Calculate the volume for a rectangular bed or a top-up layer, then turn it into whole bags using the size on your bag’s label.
Use inside measurements. For a top-up, enter only the added layer’s depth. For feet and inches, convert to decimal feet or enter the total inches. Changing a unit reinterprets the number; it does not convert it.
Leave empty for volume only. Use volume, not a bag’s weight in kg or lb.
Enter your dimensions or a known volume. Add your bag size to see how many whole bags cover that volume.
Geometric volume only. No automatic extra allowance, settling adjustment or soil-weight estimate is included. Actual fill depends on your measurements and the material.
For a rectangular area, volume = length × width × fill depth, after converting the dimensions to the same unit. 1 m³ = 1,000 L. 1 ft³ = 28.316846592 L. 1 yd³ = 764.554857984 L.
Whole bags = volume needed ÷ volume per bag, rounded up. We show the leftover volume from that rounding separately; it is not a recommended reserve.
Example: 5 m × 4 m × 10 cm = 2,000 L. With 50 L in each bag, that is 40 bags. These are illustrative inputs, not a recommended depth or bag size.
One rectangular area or one known volume, all filled with the same material. Measure the space to be filled, excluding existing soil or other fillers. Circular or tapered pots need their own volume calculation; do not treat them as rectangles.