Convert Gallons to Liters
Convert US gallons to liters instantly — exact factors, quick table, nothing uploaded.
Common conversions
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Gallons to liters, fuel tanks to aquariums
Fuel economy, aquarium volumes, paint coverage, pool capacity — gallons rule in the US, liters everywhere else. This page uses the US liquid gallon, exactly 3.785411784 liters. The UK imperial gallon is a different animal (4.54609 L, about 20% bigger), which is why the label matters.
This page presets the converter to US gallons → liters. Type 15 and you get 56.7812 L — a mid-size American fuel tank; type 55 and you get 208.198 L — the familiar blue drum, specified in gallons on one continent and liters on the other.
If you are converting a UK recipe or a British fuel figure, switch to the Volume category and note the unit names carefully. Everything here computes locally in your browser, with no upload and no limits on how often you convert.
Quick conversion table
Common values at a glance — computed locally with exact standard factors.
| Value (gal) | Converted (L) |
|---|---|
| 1 | 3.78541 |
| 2 | 7.57082 |
| 5 | 18.9271 |
| 10 | 37.8541 |
| 25 | 94.6353 |
| 50 | 189.271 |
| 100 | 378.541 |
How to convert gallons to liters
Enter US gallons
Decimal gallons fine — 12.5 for half a tank, 0.25 for a quart.
Read liters
Exact multiplication by 3.785411784, displayed to six significant digits.
Check the quick table
Common tank and container sizes are listed below for fast comparison.
FAQs about this conversion
How many liters is 1 US gallon exactly?
Exactly 3.785411784 L, defined from the US fluid system (231 cubic inches).
Why is a UK gallon bigger?
The imperial gallon was defined independently (based on 10 pounds of water), giving 4.54609 L — about 20% more than the US gallon. Always check which gallon a figure uses.
What is mpg in L/100 km terms?
Miles per gallon converts to liters per 100 km by a reciprocal formula, not a simple multiply — convert the distance with the miles-to-km page and divide fuel by these gallons-to-liters figures as a first step.
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