Estimate litres, kilograms and pounds of sand, gravel or aquasoil.
Open live calculator →A 90 × 45 cm footprint with a 5 cm bed needs about 20.3 litres of substrate.
Calculate the volume of a level substrate bed and apply an approximate density for the selected material.
The live tool updates immediately and shows the result in the units commonly used by aquarium keepers around the world.
Use average depth for a sloped aquascape.
Product density varies by grain and moisture.
Check the bag volume before ordering.
For a fish-only tank with inert sand or gravel, 3–5 cm is plenty. Planted aquariums need more root space: 5 cm at the front sloping to 7–8 cm at the back is a common aquascaping profile that also improves visual depth. Very deep beds of fine sand can develop anaerobic pockets, so if you want a deep look, build height with hardscape or coarse material underneath rather than piling fine sand alone.
Substrate is sold both by volume and by weight, and the conversion depends on the material. Dry quartz sand runs around 1.5–1.7 kg per litre, typical aquarium gravel about 1.4–1.6 kg per litre, while lightweight aquasoils can be under 1 kg per litre. The calculator applies an average density for the selected type, but bags vary by brand, grain size and moisture—check the bag's own litre figure before ordering, especially for premium aquasoil where an extra bag is expensive.
Almost no aquascape has a perfectly level bed. If you plan a slope, enter the average depth—front depth plus back depth divided by two—for a realistic total. Large rocks and wood that sit directly on the glass displace substrate, so a heavily hardscaped layout may need 10–20% less material than the flat-bed estimate. It is cheaper to keep half a bag in reserve than to over-order for a layout that mostly shows stone.
A 60 × 30 cm footprint with a 4 cm bed needs about 7.2 litres of gravel, which is roughly 11 kg. Enter your exact footprint and target depth for a precise figure.
Sand suits bottom-dwellers like corydoras and gives a natural look, but needs gentle maintenance to avoid compacting. Gravel is easier to vacuum and anchors plants adequately. Nutrient-rich aquasoil is best for demanding planted layouts but breaks down over a few years.
Yes—substrate displaces water. A 5 cm bed in a 90 × 45 cm tank occupies about 20 litres of the tank's rated capacity. Use our net water volume calculator to correct for it before dosing anything.