Equipment
Calculate how much sand, gravel, or substrate you need. Free calculator gives pounds needed for any tank size.
Calculate how much substrate you need for your aquarium. Visualize different depths and substrate types.
Standard aquarium gravel, ideal for most setups
Good depth for planted tanks
Common sizes: 5, 10, 20, or 50 lbs
Next step
Looking for bags of gravel? Find aquarium stores near you with substrate in stock.
Find stores near meQuick answer
Tank Length × Width × Desired Depth ÷ 12 = Cubic feet needed
Quick reference
How to use
The right amount of substrate is essential for plant growth, beneficial bacteria colonization, and aesthetic appeal. Our aquarium substrate calculator helps you determine exactly how much sand, gravel, or aqua soil you need for any tank size, from 10 gallon to 200+ gallon aquariums.
Measure the length and width of your tank's bottom. Use inside measurements for accuracy.
Select sand, gravel, or aqua soil. Each has different densities affecting the amount needed.
Enter your target depth. Planted tanks need 2-3 inches front, 3-4 inches back. Fish-only tanks can use 1-2 inches.
Get results in pounds and kilograms. The calculator accounts for substrate density differences.
Common sizes
Pro tips
Quick facts
Pitfalls
Learn from others' errors to ensure accurate calculations and healthy aquatic life.
Why it matters — Unnatural appearance and poor plant growth
Do this instead — Slope substrate from 2-3" front to 3-4" back
Why it matters — Cloudy water for days or weeks
Do this instead — Rinse thoroughly until water runs clear (except some plant substrates)
Why it matters — Running short due to rinsing loss and settling
Do this instead — Purchase 10-15% extra substrate
Why it matters — Reduced swimming space and anaerobic pockets
Do this instead — Keep substrate proportional to tank height
Source locally
To get the substrate you need:
Products
aquarium sand · aquarium gravel · planted substrate · aqua soil
Services
substrate installation · aquascaping services
Reference
Next up
Don't forget these important calculations:
Related topics