Gallons per hour (gal/h) to Cubic inches per hour (in³/h) conversion

Understanding Gallons per hour to Cubic inches per hour Conversion

Gallons per hour ($\text{gal/h}$) and cubic inches per hour ($\text{in}^3/\text{h}$) are both units of volume flow rate, which describes how much volume moves through a system over time. Gallons per hour is common in fuel, water, and pump specifications, while cubic inches per hour can be useful in small-scale mechanical, laboratory, or engineering contexts where inch-based dimensions are used.

Converting between these units helps express the same flow rate in a form that better matches the size of the system being measured. It is especially useful when equipment specifications, design drawings, or technical references use different unit systems.

Conversion Formula

To convert gallons per hour to cubic inches per hour, use:

$$\text{in}^3/\text{h} = \text{gal/h} \times 231.00106477053$$

To convert cubic inches per hour to gallons per hour, use:

$$\text{gal/h} = \text{in}^3/\text{h} \times 0.004328984375$$

These formulas are based on the conversion facts:

$$1\ \text{gal/h} = 231.00106477053\ \text{in}^3/\text{h}$$

and

$$1\ \text{in}^3/\text{h} = 0.004328984375\ \text{gal/h}$$

Step-by-Step Example

Suppose a metering pump delivers $18.5\ \text{gal/h}$ and the flow rate needs to be expressed in cubic inches per hour.

1. Write the formula

$$\text{in}^3/\text{h} = \text{gal/h} \times 231.00106477053$$

2. Substitute the value

$$\text{in}^3/\text{h} = 18.5 \times 231.00106477053$$

3. Calculate

$$\text{in}^3/\text{h} = 4273.519698254805$$

So,

$$18.5\ \text{gal/h} = 4273.519698254805\ \text{in}^3/\text{h}$$

Real-World Examples

• A small chemical dosing pump rated at $2.5\ \text{gal/h}$ has a flow rate of $577.502661926325\ \text{in}^3/\text{h}$.
• A fuel transfer system moving $12\ \text{gal/h}$ corresponds to $2772.01277724636\ \text{in}^3/\text{h}$.
• A water treatment feed line operating at $40\ \text{gal/h}$ equals $9240.0425908212\ \text{in}^3/\text{h}$.
• A precision lubrication system delivering $0.75\ \text{gal/h}$ provides $173.2507985778975\ \text{in}^3/\text{h}$.

Interesting Facts

• The U.S. gallon is legally defined as $231$ cubic inches, which is why gallon-based conversions to cubic-inch units are direct and widely used in U.S. customary measurements. Source: NIST Handbook 44 and Wikipedia: Gallon
• Cubic inches are often used in American engineering for compact volumes, including engine displacement and small fluid chambers, making $\text{in}^3/\text{h}$ a practical unit in inch-based mechanical design. Source: Britannica: Cubic measure

How to Convert Gallons per hour to Cubic inches per hour

To convert Gallons per hour (gal/h) to Cubic inches per hour (in3/h), multiply the flow rate by the conversion factor between gallons and cubic inches. Since the time unit is already the same in both units, only the volume part needs to be converted.

1. Write the conversion factor:
   Use the factor for this conversion:

   $$1 \text{ gal/h} = 231.00106477053 \text{ in}^3\text{/h}$$

2. Set up the multiplication:
   Multiply the given value, $25 \text{ gal/h}$, by the conversion factor:

   $$25 \text{ gal/h} \times 231.00106477053 \frac{\text{in}^3\text{/h}}{\text{gal/h}}$$

3. Cancel the original unit:
   The $\text{gal/h}$ units cancel, leaving only cubic inches per hour:

   $$25 \times 231.00106477053 = 5775.0266192633$$

   $$= 5775.0266192633 \text{ in}^3\text{/h}$$

4. Result:

   $$25 \text{ Gallons per hour} = 5775.0266192633 \text{ Cubic inches per hour}$$

A quick tip: when both units use “per hour,” you only need to convert the volume unit. Keeping track of unit cancellation helps confirm the setup is correct.

What is the formula to convert Gallons per hour to Cubic inches per hour?

To convert Gallons per hour to Cubic inches per hour, multiply the flow rate in gal/h by the factor $231.00106477053$.
The formula is: $in^3/h = gal/h \times 231.00106477053$.

How many Cubic inches per hour are in 1 Gallon per hour?

There are $231.00106477053 \, in^3/h$ in $1 \, gal/h$.
This value uses the conversion factor exactly as provided.

Why is the conversion factor $231.00106477053$ for gal/h to in3/h?

This factor expresses how many cubic inches correspond to one gallon while keeping the time unit as hours.
Because both units are rates per hour, only the volume part changes, so $1 \, gal/h = 231.00106477053 \, in^3/h$.

When would I use Gallons per hour to Cubic inches per hour in real life?

This conversion is useful in pump sizing, fluid delivery systems, engine testing, and small-scale industrial equipment where cubic inches are a more practical volume unit.
For example, a device rated in gal/h may need to be compared with component specifications listed in $in^3/h$.

How do I convert a larger flow rate from Gallons per hour to Cubic inches per hour?

Multiply the number of Gallons per hour by $231.00106477053$.
For example, if a system flows at $5 \, gal/h$, then its flow in Cubic inches per hour is found using $5 \times 231.00106477053$.

Does this conversion change if the liquid is water, oil, or fuel?

No, the unit conversion does not depend on the type of liquid.
As long as the flow is measured in Gallons per hour, you convert to Cubic inches per hour using the same factor: $231.00106477053$.