90 gallon fish tank size and measurements
How big is a 90 gallon tank? It is about 4.0 feet long (48 in), 18 inches from front to back and 24 inches tall, so it needs a stand or space at least 48 x 18 inches.
- Outside dimensions
- 48 x 18 x 24 in121.9 x 45.7 x 61 cm
- Volume
- 90 US gal341 L, 75 UK gal
- Footprint
- 6.0 sq ft864 sq in
- Water weight
- 751 lb340 kg
Measured from the outside, these dimensions hold about 89.8 US gallons. Real water volume is lower because of glass thickness, substrate, decor and the gap below the rim. Check the real figure with the aquarium volume calculator.
How much does a 90 gallon tank weigh?
A 90 gallon tank weighs about 1,011 lb (458 kg) once set up, counting the empty glass (160 lb), the water and 2 inches of gravel. Use a stand rated for the full weight, on a level floor. The fish tank weight guide compares every size.
How much gravel or sand for a 90 gallon tank?
| Bed depth | Gravel | Sand | Aquasoil |
|---|---|---|---|
| 1 in (2.5 cm) | 50 lb | 48 lb | 14 L |
| 2 in (5.1 cm) | 100 lb | 95 lb | 28 L |
| 3 in (7.6 cm) | 150 lb | 142 lb | 42 L |
Based on a 48 x 18 in floor and typical bulk densities.
Different depth? Use the aquarium substrate calculator.
Heater and filter size for a 90 gallon tank
A common rule is 3–5 watts per gallon, so a 90 gallon tank needs about 270–450 W: two 200 W heaters, one at each end suits most rooms. Use the higher end in cold rooms.
For filtration, aim to turn the water over 4–6 times an hour: a filter rated around 360–540 gallons per hour.
Fish that suit a 90 gallon tank
- Angelfish and discus, given good care
- Medium-sized cichlids
- Large community tanks
- Reef or fish-only marine setups
Starting ideas only. Check each species' adult size, temperament and water needs before buying.
Compare nearby sizes
- Next smaller: 75 gallon, 48 x 18 x 21 in
- Next larger: 100 gallon, 72 x 18 x 18 in
See every size in the aquarium size chart.
Frequently asked questions
What are the dimensions of a 90 gallon tank?
A standard 90 gallon aquarium measures about 48 x 18 x 24 inches (121.9 x 45.7 x 61 cm), length x width x height. Brands vary by a fraction of an inch.
How long is a 90 gallon tank?
About 48 inches (121.9 cm), or 4.0 feet.
How big is a 90 gallon tank?
It is about 4.0 feet long, 18 inches deep and 24 inches tall, and takes up 6.0 square feet of floor.
How much does a 90 gallon tank weigh when full?
About 1,011 lb (458 kg) once set up, counting the empty glass (160 lb), the water and 2 inches of gravel.
How much gravel do I need for a 90 gallon tank?
For a 2 inch bed, about 100 lb of gravel or 95 lb of sand.
What size heater does a 90 gallon tank need?
About 270–450 watts in total, so two 200 W heaters, one at each end suits most rooms.
Last updated .