Count the pounds.
Fill the box.
Start with the footprint. Choose the depth and material. We’ll estimate the weight, compare the bag mix, and work out the boxes.
Presets describe common nominal footprints. Measure the inside of your actual tank or enclosure.
Estimated material weight
Tax is not included. The cart recalculates shipping with your other materials.
- Volume: 0.333 cubic feet.
- Estimated bulk density: 50 lb per cubic foot.
- Pounds = footprint × depth ÷ 1,728 × bulk density, with dimensions converted to inches.
- Bag quantities round up. The lowest product-price combination can include a little extra material. Density and physical packing still need real-world calibration.
The floor matters
more than gallons.
A gallon measures water volume. It does not describe the floor beneath that water. Two tanks with the same nominal capacity can have different lengths and widths, so a universal pounds-per-gallon rule misses the part you are actually covering. Measure the inside footprint of your tank, pond, or enclosure instead.
For a rectangle, multiply length by width and the depth you want. For a circle, use the diameter to calculate the area, then multiply by depth. The calculator converts those dimensions into cubic feet and multiplies by the selected material’s bulk density. You can switch between inches, centimeters, and feet without starting again.
Density makes the difference between a layer and a bag. Porous lava rock occupies more room per pound than dense pebble. Loose mulch is lighter still. Our starting densities are estimates that will be corrected with measured material. Your result is a planning weight, not a guarantee that every natural batch packs identically.
Think about the shape of the finished surface. A tank with a deeper back and a shallower front needs an average depth. Large rocks and wood displace some of the volume, while gaps around them and extra material for maintenance can change the amount you keep on hand. Avoid adding a large arbitrary allowance before you have measured the actual space.
The bag calculation compares whole 1 lb and 5 lb bags. Sometimes a 5 lb bag costs less than enough individual 1 lb bags, even when it leaves a small surplus. Shipping is calculated separately because each material occupies a different share of a flat-rate box. Adding this estimate to an existing cart can change the combined box plan.
The layer builder gives you a way to adjust a proposed floor, not a universal husbandry recipe. A tropical drainage layer needs a barrier above it and a way to manage excess water. An arid enclosure needs a substrate plan matched to the species, temperature, and moisture. Materials awaiting their required confirmations remain unavailable to add.
Use the field guides to check the assumptions behind your plan. Then compare the confirmed product details with your own habitat before placing an order.