Utility July 13, 2026 · 8 Min Read

Gallons to Liters Calculator – Guide & Formulas

Convert US and UK gallons to liters (gal to L) instantly with high precision.

Convert liquid volumes between standard gallons and metric liters. Supports both US liquid gallons and UK (Imperial) gallons.

Key Takeaway

Use the free Gallons to Liters Calculator to convert us and uk gallons to liters (gal to l) instantly with high precision. Get instant results with step-by-step explanations.

How to Use the Gallons to Liters Calculator

  1. Enter the volume value.
  2. Choose whether your input is in US Liquid Gallons or UK Imperial Gallons.
  3. View the computed metric value in liters (L).

The Formula

Liters = Gallons * 3.785411784 (US) or Gallons * 4.54609 (UK)

Variable Definitions

  • Gallons: The input volume in standard US or Imperial gallons
  • Liters: The calculated metric volume equivalent

Converting a Fuel Tank

A car fuel tank holds 15 US gallons of gasoline. Find its capacity in liters.

  1. Step 1: Input Gallons = 15, Type = US Gallons.
  2. Step 2: Multiply by 3.785411784.
  3. Step 3: 15 * 3.78541 = 56.781 Liters.

Frequently Asked Questions

What is the difference between US and UK gallons?

A US gallon is defined as 231 cubic inches (approx. 3.785 liters), while a UK (Imperial) gallon is defined as exactly 4.54609 liters (approx. 20% larger than a US gallon).