Tank Volume Calculator
Your estimate
Tank capacity470 gal1,779.2 L
- Liquid in the tank
- 282 gal1,067.5 L
- Filled
- 60%
- Volume
- 1.779 m³62.83 ft³ · 470 gal
Total capacity and how much is in the tank at a given fill height.
Updated 2026-10-20 · Based on: exact volume formulas (1 US gal = 3.785 L).
How to use the Tank Volume Calculator
- Pick vertical cylinder, horizontal cylinder or rectangular tank.
- Enter the sizes.
- Enter the liquid height to see the filled volume.
Formula
Vertical: π r² h. Horizontal: the filled part is the circular segment r² arccos((r − h)/r) − (r − h)√(2rh − h²), times the length.
Rectangular: l × w × h.
Worked example
With the values preset in the calculator above: (Vertical)
- Diameter
- 4 ft
- Height
- 5 ft
- Liquid height
- 3 ft
- Tank capacity
- 470 gal (1,779.2 L)
- Liquid in the tank
- 282 gal (1,067.5 L)
- Filled
- 60%
- Volume
- 1.779 m³ (62.83 ft³)
Frequently asked questions
How much is in a horizontal tank half full?
Exactly half — but at quarter height it is less than a quarter, because the tank is narrow at the bottom.
How many gallons in a 4 ft by 8 ft horizontal tank?
752 gal in total.
Litres to gallons?
1 US gallon = 3.785 L.
More calculators
Estimates only — check quantities with your supplier and local building code before you order.