Calculate gallons from cubic inches, constant base area and depth, rectangular tank dimensions, or a vertical cylinder’s inside diameter and liquid depth. Choose US liquid or Imperial gallons.

A length alone cannot determine a liquid volume.

Use inside dimensions. Cylinder mode assumes a vertical circular cylinder, not a partially filled horizontal tank. Liquid height must stay within the actual container.

Precision (default 2 decimals)

Inches To Gallons Formula

The following formula is used to calculate the volume of liquid in gallons from a measurement in inches.

V = A × h × CF

Variables:

  • V is the volume of the liquid in gallons (gal)
  • A is the cross-sectional area of the container (in^2)
  • h is the height or depth of the liquid (in)
  • CF is the selected gallon conversion: exactly 1/231 US liquid gal/in^3, or 0.016387064/4.54609 Imperial gal/in^3. The value 0.004329 is a rounded US factor.

To calculate the volume of the liquid in gallons, multiply the cross-sectional area of the container by the height or depth of the liquid. Then multiply the result by the conversion factor from cubic inches to gallons.

Inches to Gallons Conversion Table (Assumes cross-sectional area = 1 ft² = 144 in²)
Height (in) US liquid gallons (gal)
¼0.156
½0.312
10.623
21.247
31.870
42.494
63.740
84.987
106.234
127.481
159.351
1811.221
2414.961
3018.701
3622.442
4024.935
4829.922
6037.403
7244.883
9659.844
* Rounded to 3 decimals. Formula: gallons = area(in²) × height(in) ÷ 231. With area = 1 ft² (144 in²), per inch ≈ 0.623 gal/in.

What is Inches To Gallons?

Inches to Gallons is a conversion method typically used to calculate the volume of liquid in a cylindrical or rectangular container. It involves converting the height or depth measurement (in inches) of the liquid into its volume (in gallons). This is often used in scenarios such as measuring the amount of fuel in a tank or water in a pool. The gallon definition fixes the volume conversion factor. Shape and inside dimensions determine liquid volume; a constant area times liquid depth applies to rectangular tanks and vertical cylinders, not a partly filled horizontal cylinder.

How to Calculate Inches To Gallons?

The following steps outline how to calculate the Inches To Gallons using the formula V = A * h * CF.

  1. First, determine the cross-sectional area of the container (A) in square inches (in^2).
  2. Next, determine the height or depth of the liquid (h) in inches (in).
  3. Next, gather the conversion factor (CF) from cubic inches to gallons (gal/in^3), using 1/231 for US liquid gallons or 0.016387064/4.54609 for Imperial gallons.
  4. Finally, calculate the volume of the liquid (V) in gallons (gal) using the formula V = A * h * CF.
  5. After inserting the values for A, h, and CF, calculate the result to obtain the volume of the liquid in gallons.

Example Problem:

Use the following variables as an example problem to test your knowledge:

Cross-sectional area of the container (A) = 10 in^2

Height or depth of the liquid (h) = 5 in

Conversion factor (CF) = 0.004329 gal/in^3