Tank Volume Calculator
Calculate volume for horizontal cylinders, vertical tanks, oval, capsule, and rectangular tanks. Get fill levels, gallons, liters, and strapping charts.
Tank Volume
Total Capacity
564.02
US Gallons
Tank Shape
Cylindrical tank lying on its side (fuel tanks, water tanks)
Common Tank Sizes
Tank Visualization
Tank Dimensions
Fill Level
Quick fill calculator:
Capacity Planning
Days Remaining
56.4
at 5 gal/day
Liquid Weight
2352
pounds (Water)
Refill When
113
gallons (20% full)
Strapping Chart
Tank Volume Formulas
Horizontal Cylinder (full)
V = pi x r^2 x L
Vertical Cylinder
V = pi x r^2 x h
Rectangle
V = L x W x H
Sphere
V = (4/3) x pi x r^3
Conversion
US Gallons = Cubic Inches / 231
Liquid Density Reference
Water
8.34
lbs/gal
Diesel Fuel
7.1
lbs/gal
Gasoline
6.1
lbs/gal
Heating Oil
7.2
lbs/gal
Propane
4.2
lbs/gal
Kerosene
6.8
lbs/gal
Motor Oil
7.5
lbs/gal
Milk
8.6
lbs/gal
Quick Answer
For a horizontal cylinder tank: Full Volume = pi x radius^2 x length. For partial fill, use the segment formula based on fill depth. Vertical cylinder: Volume = pi x radius^2 x height. Rectangular tank: Volume = length x width x height. Convert cubic inches to US gallons by dividing by 231.
Key Facts
- Horizontal Cylinder (full): V = pi x r^2 x L
- Vertical Cylinder: V = pi x r^2 x h
- Rectangle: V = L x W x H
- Sphere: V = (4/3) x pi x r^3
- 1 US gallon = 231 cubic inches = 3.785 liters
- 1 Imperial gallon = 277.42 cubic inches = 4.546 liters
- Standard oil tank (275 gal): 60" x 27" diameter
- Propane tank (500 gal): 120" x 37.5" diameter
- 1 cubic foot = 7.48 US gallons
Frequently Asked Questions
For cylindrical tanks: V = pi x radius^2 x length (or height). For rectangular tanks: V = length x width x height. For oval tanks: V = (pi/4) x width x height x length. Always use consistent units and convert the final answer to gallons or liters.
For horizontal cylinders, partial fill volume uses the circular segment formula: V = L x [r^2 x arccos((r-h)/r) - (r-h) x sqrt(2rh - h^2)], where L is length, r is radius, and h is fill height. This calculator handles this complex math automatically.
Calculate volume in cubic inches (pi x radius^2 x length), then divide by 231 for US gallons or 277.42 for Imperial gallons. Example: 48" diameter x 72" long = pi x 24^2 x 72 = 130,288 cu in / 231 = 564 US gallons.
A strapping chart (or tank calibration chart) shows the volume at each inch of fill depth. It's used for inventory measurement in fuel tanks. For horizontal cylinders, volume doesn't increase linearly with depth due to the curved shape.
Multiply volume (gallons) by the liquid density: Water = 8.34 lbs/gal, Diesel = 7.1 lbs/gal, Gasoline = 6.1 lbs/gal, Heating Oil = 7.2 lbs/gal, Propane = 4.2 lbs/gal.
Divide current volume by daily usage rate. Example: 500 gallons tank, 50% full (250 gal), using 5 gallons/day = 250/5 = 50 days remaining. Add a safety margin and refill at 20-25% to avoid running empty.
Calculate daily usage x days between deliveries x 1.2 (safety factor). For home heating oil: ~3-5 gal/day in winter. For propane: ~1-2 gal/day heating. Water storage: 50-100 gal/person/day emergency supply.
For a horizontal oval tank: V = (pi/4) x width x height x length. For vertical oval: V = (pi/4) x width x depth x height. The pi/4 factor (~0.785) accounts for the elliptical cross-section.
Tank Volume
Total Capacity
564.02
US Gallons