A tank volume calculator determines the capacity of storage tanks in various shapes — vertical cylinders, horizontal cylinders, rectangular tanks, and elliptical tanks. Enter dimensions for instant results.
Tank volume is the total capacity of a storage container, measured in liters (L), gallons (gal), or cubic meters (m³). Tanks come in four common configurations:
Vertical cylinder: V = πr²h.
Horizontal cylinder: V = πr²L (total); partial fill requires integration or lookup tables.
Rectangular: V = L × W × H.
Elliptical: V = π × a × b × L (where a and b are the semi-axes of the ellipse cross-section).
Example: Vertical tank, diameter 2 m, height 3 m: V = π × 1² × 3 = 9.42 m³ = 9,425 L = 2,490 gal.
Vertical, D=1.2m, H=1.5m: V = π×0.6²×1.5 = 1.696 m³ = 1,696 L = 448 gal.
Horizontal, D=96.5cm, L=304.8cm: V = π×48.25²×304.8 = 2,229,043 cm³ ≈ 2,229 L ≈ 589 gal.
3 × 2 × 1.5 m: V = 9 m³ = 9,000 L = 2,378 gal.
Semi-axes 0.9m × 1.2m, length 6m: V = π×0.9×1.2×6 = 20.36 m³ = 20,358 L.
35 free volume calculation tools — click any calculator to get started.
Answers to common questions about the tank volume calculator.
For a vertical round tank: V = πr²h where r = radius (half the diameter) and h = height. Convert cm³ to liters by dividing by 1,000.
For a horizontal cylinder partially filled to depth d: V = L × [r²×arccos((r-d)/r) - (r-d)×√(2rd-d²)]. This is complex — use this calculator for instant results.
1,000 liters = 264.17 US gallons = 219.97 Imperial gallons.
Average household uses 300-400 liters/day. For 3 days backup: 900-1,200 L tank. For a family of 4 at 80 gal/day: minimum 250 gallon tank for 3-day supply.
Nominal capacity is the manufacturer's rated volume. Actual (working) capacity is typically 80-85% of nominal to allow for expansion, air space, and safe filling limits.