What is Gallons to Liters Converter?

This tool converts US gallons to liters, bridging the gap between American and international volume measurements. If you're traveling abroad, comparing fuel efficiency, or working with metric specifications, this converter provides the instant accuracy you need.

The Conversion Factor

One US gallon equals exactly 3.785411784 liters. For quick mental math, remember that a gallon is roughly 3.8 liters or just under 4 liters.

Common Applications

International travelers: Understanding fuel costs when driving abroad
Car enthusiasts: Comparing vehicle specifications from different markets
Expats: Adapting to metric measurements in a new country
Online shoppers: Converting product sizes from US retailers

Tank Size Context

Understanding real-world conversions helps with planning:

Compact car tank (12 gal) = 45 liters
Sedan tank (15 gal) = 57 liters
SUV/Truck tank (20-25 gal) = 75-95 liters

Privacy

All calculations happen locally in your browser. No data is collected or transmitted.

How to Use

Converting gallons to liters is straightforward:

Enter the gallon value in the first field
See the liter result appear instantly
Copy the result if needed for other applications

Bidirectional Conversion

Need liters to gallons instead? Click the swap button or type directly in the liter field. Both directions work seamlessly.

Quick Estimation Method

For rough calculations without a calculator:

Multiply gallons by 4, then subtract 5%
Example: 10 gallons × 4 = 40, minus 5% = 38 liters (actual: 37.85)
This gives you a close estimate within 1%

Practical Examples

Fuel purchase: You bought 15 gallons = 56.8 liters
Recipe scaling: 2 gallons of water = 7.6 liters
Pool chemicals: Treatment for 10,000 gallons = 37,854 liters

Features

Precise Conversion

Uses the exact conversion factor: 1 gallon = 3.785411784 liters. Results are accurate to multiple decimal places for scientific and engineering applications.

Real-Time Calculation

No need to press a calculate button. Results update as you type, making it fast to check multiple values.

Copy Functionality

One-click copy for the result. Paste directly into spreadsheets, documents, or other applications.

Reference Table

Quick reference for common gallon amounts:

1 gallon = 3.79 liters
5 gallons = 18.93 liters
10 gallons = 37.85 liters
20 gallons = 75.71 liters

Unit Flexibility

While focused on gallons and liters, you can switch to other volume units using the dropdown menus for additional conversions.

Mobile Friendly

Works perfectly on phones and tablets. The numeric keypad appears automatically for easy input on touch devices.

Frequently Asked Questions

How many liters are in a gallon?

One US gallon equals 3.785 liters. This is the liquid gallon used for fuel, beverages, and most liquid measurements in the United States.

Why is a US gallon different from a UK gallon?

Historical differences in measurement standards. The US gallon (3.785 L) is based on the wine gallon, while the UK imperial gallon (4.546 L) was standardized differently in 1824. The UK gallon is about 20% larger.

How do I convert my car's fuel economy?

To convert MPG (miles per gallon) to L/100km: divide 235.21 by your MPG. For example, 30 MPG = 235.21 ÷ 30 = 7.84 L/100km.

How much is 5 gallons in liters?

5 US gallons = 18.93 liters. This is a common size for water jugs and fuel containers.

What's an easy way to remember the conversion?

Remember that 1 gallon is slightly less than 4 liters. For quick estimates, multiply gallons by 4 and you'll be within 6% of the exact answer.

Are liquid and dry gallons the same?

No. A US liquid gallon is 3.785 liters, while a US dry gallon is 4.405 liters. This converter uses liquid gallons, which is standard for fuels and beverages.

Gallons to Liters