Gallons to Liters Converter

Instant US volume conversion — both ways, with the exact formula.

FREE TOOL · WORKS OFFLINE · NO SIGN-UP
Converting: gal → L
Result in liters (L)
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Formula: liters = US gallons × 3.78541

This converter uses US liquid gallons (1 gal = 3.78541 L). Type any volume — the result updates as you type. Use Swap to convert liters back to gallons.

📋 Gallons to Liters Quick Table

US gallons (gal)Liters (L)Common use
1 gal3.78541 LMilk jug
5 gal18.9271 LWater cooler bottle
10 gal37.8541 LFish tank (small)
15 gal56.7812 LTypical car fuel tank
50 gal189.271 LWater heater

🧴 How to Use This Gallons to Liters Converter

  1. 1.Type a volume. The converted value appears instantly — no button to press, no page reload.
  2. 2.Swap the direction. The ⇄ button flips the converter so you can turn liters back into US gallons just as fast.
  3. 3.Mind the gallon type. This tool uses US liquid gallons. A UK imperial gallon is larger (4.54609 L), so check which one your source uses.
  4. 4.Use the quick table. Everyday volumes — milk jugs, fuel tanks, water heaters — are listed for a fast sanity check.

❓ FAQ

How do you convert gallons to liters?

Multiply the volume in US gallons by 3.78541. Formula: liters = gallons × 3.78541. For example, 5 gallons × 3.78541 = 18.9271 liters (about 18.93 L).

How many liters are in 1 US gallon?

One US liquid gallon is 3.78541 liters (exactly 3.785411784 L). Note that a UK (imperial) gallon is bigger — 4.54609 liters — so make sure you know which gallon a recipe or tank spec uses. This converter uses US gallons.

How do you convert liters back to gallons?

Divide the volume in liters by 3.78541. Formula: gallons = liters ÷ 3.78541. For example, 18.9271 L ÷ 3.78541 = 5 gallons. The swap button on this page reverses the direction instantly.

Is this gallons to liters converter free?

Yes — 100% free, no sign-up. The conversion happens entirely in your browser; nothing is uploaded, saved or tracked.

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