Gallons to Liters Converter
Convert gallons to liters — and back — in an instant. Type a value in either box and the answer updates live. It’s accurate, free and completely private: the conversion runs entirely on your device.
- 🔒 100% private — no uploads
- 🆓 Free, no watermark
- 📱 Works on any device
How to convert
- 1
Choose your units
The tool opens on the most common pairing. Change either unit from its dropdown, or hit the swap button to flip the direction.
- 2
Type a value
Enter a number in either box. The other side updates instantly as you type — convert either way without pressing a button.
- 3
Copy or compare
Copy the result to your clipboard, or scan the common-values table below for quick at-a-glance conversions.
Why use Gallons to Liters Converter?
100% private
Every conversion is computed locally in your browser. Nothing you enter ever leaves your device.
Instant & two-way
Results update live as you type, in either direction — no “convert” button and no page reloads.
Accurate
Conversions use exact, standards-based factors, so you get the same answer a trusted reference would.
Works on any device
No install and no account — it runs in any modern browser on desktop, tablet or phone.
The gallons to liters formula
Multiply US gallons by 3.78541 to get liters: L = gal × 3.78541. A 15-gallon tank is 15 × 3.78541 ≈ 56.8 L. For imperial (UK) gallons, the factor is 4.54609 — an imperial gallon is about 20% bigger than a US one.
Everyday gallon values
1 gallon is 3.79 L, 5 gallons (a big water jug) is 18.9 L, and 12 gallons of gasoline is 45.4 L. If a recipe or spec sheet just says “gallon”, assume US unless it comes from the UK, Ireland or Canada — the difference is large enough to matter.
Frequently asked questions
How do I convert gallons to liters?
Type the number of gallons in the first box and read the result in liters — it updates as you type. To go the other way, type in the liters box instead.
Does anything get uploaded to a server?
No. The conversion runs entirely in your browser with JavaScript — nothing you type is uploaded, stored or logged, and it keeps working offline once the page has loaded.
Is it free?
Yes — completely free, no account, no watermark and no limits.