45 gallon fish tank size and measurements
How big is a 45 gallon tank? It is about 3.0 feet long (36 in), 12 inches from front to back and 24 inches tall, so it needs a stand or space at least 36 x 12 inches.
- Outside dimensions
- 36 x 12 x 24 in91.4 x 30.5 x 61 cm
- Volume
- 45 US gal170 L, 37 UK gal
- Footprint
- 3.0 sq ft432 sq in
- Water weight
- 375 lb170 kg
Checked against the manufacturer's specs: the Aqueon 45 gallon measures 36 1/4 x 12 5/8 x 23 3/4 in outside, 69 lb empty. The size above is the rounded standard size most charts use.
Measured from the outside, these dimensions hold about 44.9 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 45 gallon tank weigh?
A 45 gallon tank weighs about 494 lb (224 kg) once set up, counting the empty glass (69 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 45 gallon tank?
| Bed depth | Gravel | Sand | Aquasoil |
|---|---|---|---|
| 1 in (2.5 cm) | 25 lb | 24 lb | 7 L |
| 2 in (5.1 cm) | 50 lb | 48 lb | 14 L |
| 3 in (7.6 cm) | 75 lb | 71 lb | 21 L |
Based on a 36 x 12 in floor and typical bulk densities.
Different depth? Use the aquarium substrate calculator.
Heater and filter size for a 45 gallon tank
A common rule is 3–5 watts per gallon, so a 45 gallon tank needs about 135–225 W: one 200 W heater 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 180–270 gallons per hour.
Fish that suit a 45 gallon tank
- Angelfish
- Gouramis
- Tetra schools that use the middle and top of the tank
- Tall plants such as vallisneria
Starting ideas only. Check each species' adult size, temperament and water needs before buying.
Compare nearby sizes
- Next smaller: 40 gallon breeder, 36 x 18 x 16 in
- Next larger: 50 gallon, 36 x 18 x 19 in
- Same 36 x 12 in footprint: 30 gallon, 16 in tall
- Same 36 x 12 in footprint: 38 gallon, 20 in tall
See every size in the aquarium size chart.
Frequently asked questions
What are the dimensions of a 45 gallon tank?
A standard 45 gallon aquarium measures about 36 x 12 x 24 inches (91.4 x 30.5 x 61 cm), length x width x height. Brands vary by a fraction of an inch.
How long is a 45 gallon tank?
About 36 inches (91.4 cm), or 3.0 feet.
How big is a 45 gallon tank?
It is about 3.0 feet long, 12 inches deep and 24 inches tall, and takes up 3.0 square feet of floor.
How much does a 45 gallon tank weigh when full?
About 494 lb (224 kg) once set up, counting the empty glass (69 lb), the water and 2 inches of gravel.
How much gravel do I need for a 45 gallon tank?
For a 2 inch bed, about 50 lb of gravel or 48 lb of sand.
What size heater does a 45 gallon tank need?
About 135–225 watts in total, so one 200 W heater suits most rooms.
Last updated .