Gallons per hour (gal/h) to Litres per hour (l/h) conversion

Understanding Gallons per hour to Litres per hour Conversion

Gallons per hour (gal/h) and litres per hour (l/h) are both units of volumetric flow rate, meaning they describe how much liquid moves or is delivered in one hour. Gallons per hour is commonly seen in systems that use U.S. customary units, while litres per hour is used in metric-based contexts.

Converting between these units is useful in applications such as fuel consumption, pump output, irrigation equipment, filtration systems, and industrial process control. It allows flow rates to be compared consistently across equipment specifications, technical documents, and regional measurement standards.

Conversion Formula

To convert gallons per hour to litres per hour, multiply by the conversion factor:

$$1 \text{ gal/h} = 3.7854117842063 \text{ l/h}$$

So the formula is:

$$\text{l/h} = \text{gal/h} \times 3.7854117842063$$

For the reverse conversion:

$$1 \text{ l/h} = 0.2641720523438 \text{ gal/h}$$

So:

$$\text{gal/h} = \text{l/h} \times 0.2641720523438$$

Step-by-Step Example

Suppose a pump delivers $18.5 \text{ gal/h}$.

Write the formula:

$$\text{l/h} = \text{gal/h} \times 3.7854117842063$$

Substitute the value:

$$\text{l/h} = 18.5 \times 3.7854117842063$$

Calculate:

$$18.5 \text{ gal/h} = 70.03011700781655 \text{ l/h}$$

So a flow rate of $18.5 \text{ gal/h}$ is equal to $70.03011700781655 \text{ l/h}$.

Real-World Examples

• A small chemical dosing pump rated at $2.5 \text{ gal/h}$ is used for water treatment and can also be expressed in litres per hour for metric documentation.
• An aquarium filtration or circulation device may move about $12 \text{ gal/h}$, which is often converted when comparing international product specifications.
• A drip irrigation controller supplying $25 \text{ gal/h}$ across a garden zone may need conversion for farm equipment manuals that list values in litres per hour.
• A fuel transfer setup delivering $40 \text{ gal/h}$ can be compared with European pump ratings that use litres per hour instead of gallons per hour.

Interesting Facts

• The litre is a metric unit of volume widely accepted for use with the International System of Units, although it is not an SI base unit. Source: NIST - SI Units
• The gallon varies by system, and the U.S. gallon is different from the imperial gallon, which is one reason conversions involving gallons must use the correct standard. Source: Wikipedia - Gallon

Summary

Gallons per hour and litres per hour both measure the rate of liquid flow over time. The factor for this conversion is:

$$1 \text{ gal/h} = 3.7854117842063 \text{ l/h}$$

This means any value in gallons per hour can be converted to litres per hour by multiplying by $3.7854117842063$.

For reverse conversions, the factor is:

$$1 \text{ l/h} = 0.2641720523438 \text{ gal/h}$$

This relationship is useful in engineering, plumbing, fuel systems, agriculture, and laboratory settings where both customary and metric flow-rate units may appear.

Quick Reference

$1 \text{ gal/h} = 3.7854117842063 \text{ l/h}$

$5 \text{ gal/h}$ can be converted using:

$$\text{l/h} = 5 \times 3.7854117842063$$

$10 \text{ gal/h}$ can be converted using:

$$\text{l/h} = 10 \times 3.7854117842063$$

$50 \text{ gal/h}$ can be converted using:

$$\text{l/h} = 50 \times 3.7854117842063$$

These examples follow the same rule: multiply the gallons-per-hour value by the factor to obtain litres per hour.

How to Convert Gallons per hour to Litres per hour

To convert Gallons per hour (gal/h) to Litres per hour (l/h), multiply the flow rate by the gallon-to-litre conversion factor. Since this is a rate, the "per hour" part stays the same and only the volume unit changes.

1. Write the conversion factor:
   Use the factor for Gallons per hour to Litres per hour:

   $$1 \text{ gal/h} = 3.7854117842063 \text{ l/h}$$

2. Set up the conversion formula:
   Multiply the given value in gal/h by the conversion factor:

   $$\text{l/h} = \text{gal/h} \times 3.7854117842063$$

3. Substitute the given value:
   Insert $25$ for the flow rate in gallons per hour:

   $$\text{l/h} = 25 \times 3.7854117842063$$

4. Calculate the result:
   Perform the multiplication:

   $$25 \times 3.7854117842063 = 94.635294605158$$

5. Result:

   $$25 \text{ gal/h} = 94.635294605158 \text{ l/h}$$

A quick check is to note that $25 \times 4$ is about $100$, so $94.635294605158$ l/h is a reasonable result. For any gal/h to l/h conversion, use the same multiplication method.

What is the formula to convert Gallons per hour to Litres per hour?

To convert Gallons per hour to Litres per hour, multiply the flow rate in gal/h by the factor $3.7854117842063$. The formula is: $l/h = gal/h \times 3.7854117842063$. This gives the equivalent flow rate in Litres per hour.

How many Litres per hour are in 1 Gallon per hour?

There are exactly $3.7854117842063$ Litres per hour in $1$ Gallon per hour. This comes directly from the conversion factor: $1\ \text{gal/h} = 3.7854117842063\ \text{l/h}$.

When would I need to convert Gallons per hour to Litres per hour?

This conversion is useful when comparing pump capacity, fuel consumption, irrigation flow, or industrial liquid transfer rates across systems that use different unit standards. For example, equipment specifications in the U.S. may list flow in gal/h, while many international documents use l/h.

Is Gallons per hour a measure of volume or flow rate?

Gallons per hour is a measure of volumetric flow rate, not just volume. It describes how much liquid passes through a system each hour, and converting to Litres per hour keeps the same time basis while changing the volume unit.

Can I convert decimal Gallons per hour values to Litres per hour?

Yes, decimal values convert the same way as whole numbers. Multiply the gal/h value by $3.7854117842063$ to get l/h, whether the input is $0.5$, $2.75$, or any other decimal number.

Why is the conversion factor for gal/h to l/h $3.7854117842063$?

The factor $3.7854117842063$ comes from the relationship between one gallon and one litre. Since the time unit is already per hour on both sides, only the volume unit changes, so $1\ \text{gal/h} = 3.7854117842063\ \text{l/h}$.