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  1. Home
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  3. Tank Volume Calculator

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

Fill Level50%
Filled (US gal)282.01
Empty (US gal)282.01
Total Liters2,135.03
Filled Liters1,067.52
UK Gallons469.64
Cubic Feet75.4
Surface Area100.53 sq ft

Tank Shape

Cylindrical tank lying on its side (fuel tanks, water tanks)

Common Tank Sizes

Tank Visualization

Tank Dimensions

Fill Level

24
048

Quick fill calculator:

At 50% full =282.01 gallons

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.

Cylinder: pi x r^2 x L. Rectangle: L x W x H. Convert to gallons.

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.

Use circular segment formula. Enter fill depth and the calculator handles the math.

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.

Volume (cu in) / 231 = US gallons. 48" x 72" tank = 564 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.

A chart showing volume at each inch of fill depth for inventory measurement.

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.

Gallons x density. Water: 8.34 lb/gal. Diesel: 7.1 lb/gal. Gas: 6.1 lb/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.

Current gallons / daily usage = days remaining. Refill at 20-25%.

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.

Daily use x days between fills x 1.2. Heating oil: 3-5 gal/day winter.

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.

V = 0.785 x width x height x length for horizontal oval tanks.

Tank Volume

Total Capacity

564.02

US Gallons

Fill Level50%
Filled (US gal)282.01
Empty (US gal)282.01
Total Liters2,135.03
Filled Liters1,067.52
UK Gallons469.64
Cubic Feet75.4
Surface Area100.53 sq ft