400 gallon tank: dimensions that work
400 gal = 1,514 L = 53.5 ft³. Full weight ≈ 3,338 lb of water. Below: every diameter/length pair that holds exactly this — geometry, not brand specs, so you can sanity-check any manufacturer sheet.
| Diameter | Length |
|---|---|
| 24 in dia | 204 in (17.0 ft) |
| 30 in dia | 131 in (10.9 ft) |
| 36 in dia | 91 in (7.6 ft) |
| 38 in dia | 81 in (6.8 ft) |
| 42 in dia | 67 in (5.6 ft) |
| 48 in dia | 51 in (4.3 ft) |
| Diameter | Height |
|---|---|
| 30 in dia | 131 in tall |
| 36 in dia | 91 in tall |
| 38 in dia | 81 in tall |
| 42 in dia | 67 in tall |
| 48 in dia | 51 in tall |
Have a real tank with these dimensions? Generate its inch-by-inch dip chart, or run partial fills on the universal calculator. Manufactured tanks add heads, legs and fittings — treat these tables as the geometric core and trust the nameplate where one exists.
FAQ
How big is a 400 gallon tank?
It depends on the proportions — the tables above show every horizontal length and vertical height that holds exactly 400 gallons at common diameters. Pure geometry: πr²L = 400 × 231 in³.
How much does 400 gallons weigh?
About 3,338 lb as water or 2,820 lb as diesel — grade ranges and more liquids on the weight library.
How many litres is 400 gallons?
1,514 litres (1.5 m³). Exact: 1 US gal = 3.785411784 L.