How much gravel do I need for a 29 gallon tank?

A 29 gallon tank has a 30 by 12 inch footprint, so 2 inches of gravel is 720 cubic inches — about 40 pounds, or two 20 lb bags. For 3 inches, buy three bags.

Is one pound of gravel per gallon right?

It is a rough rule that gives about one inch of gravel in a standard tank. Tall tanks have a small footprint for their volume and need less; long and breeder tanks need more. Calculating from the footprint is more accurate.

How deep should aquarium gravel be?

About 2 inches for most freshwater tanks, 2.5 to 3 inches for planted tanks with rooted plants, and 1 inch or a bare bottom for tanks that need easy cleaning, such as breeding or quarantine tanks.

How much sand do I need for a 55 gallon tank?

A 55 gallon tank is 48 by 13 inches. At 2 inches deep that is 1,248 cubic inches, or about 72 pounds of aquarium sand — four 20 lb bags.

Volume & Weight

Aquarium Gravel Calculator

The old rule of one pound of gravel per gallon only works for a thin layer in a standard tank. This aquarium gravel calculator uses the tank's actual footprint and your target depth to give the pounds of gravel, sand, or aqua soil to buy, and the number of bags.

What you'll need

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GloFish Aquarium Gravel, Pink/Green/Blue Mix, Complements GloFish Tanks, 5 Pounds

$7.29

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Tetra Water Cleaner Gravel Siphon for Aquariums Up to 55 Gal

$10.29

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Laifoo 5ft-S Aquarium Siphon Vacuum Cleaner for Fish Tank Cleaning Gravel & Sand

$9.99

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GloFish Aquarium Gravel, Fish Tank Gravel, Black With Fluorescent Accents, Compliments GloFish Tanks, 5 lb Bag

$7.29

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Prices as of Sep 25, 2026, 6:18 PM UTC. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.

Get the Gravel & Stone Calculator app for Android

Estimate gravel, stone, sand, and mulch on the job site, save projects, and share quantities with your supplier.

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Frequently asked questions

How much gravel do I need for a 29 gallon tank?: A 29 gallon tank has a 30 by 12 inch footprint, so 2 inches of gravel is 720 cubic inches — about 40 pounds, or two 20 lb bags. For 3 inches, buy three bags.
Is one pound of gravel per gallon right?: It is a rough rule that gives about one inch of gravel in a standard tank. Tall tanks have a small footprint for their volume and need less; long and breeder tanks need more. Calculating from the footprint is more accurate.
How deep should aquarium gravel be?: About 2 inches for most freshwater tanks, 2.5 to 3 inches for planted tanks with rooted plants, and 1 inch or a bare bottom for tanks that need easy cleaning, such as breeding or quarantine tanks.
How much sand do I need for a 55 gallon tank?: A 55 gallon tank is 48 by 13 inches. At 2 inches deep that is 1,248 cubic inches, or about 72 pounds of aquarium sand — four 20 lb bags.