Gallons to Liters Conversion Formula — How to Convert gal to L
liters = gallons × 3.78541
Quick estimate: multiply by 4, then subtract 5%. For 10 gallons, 40 minus 2 is 38 L (exact: 37.85).
Step-by-Step gal to L Conversion Examples:
- •A 5-gallon bucket:5 × 3.78541 =18.93 L
- •A 15-gallon car fuel tank:15 × 3.78541 =56.78 L
- •A 55-gallon drum:55 × 3.78541 =208.20 L
- •10 UK (imperial) gallons:10 × 4.54609 =45.46 L
Why the Gallons to Liters Conversion Works & Common gal to L Converter Mistakes to Avoid
A US liquid gallon is defined as exactly 231 cubic inches, which equals 3.785411784 liters. The 3.78541 used here is that figure rounded to five decimals. The factor applies to the US liquid gallon only, not to the US dry gallon (4.405 L) or the UK imperial gallon (4.546 L).
The Common gal to L Converter Mistake: Using the US factor for a UK imperial gallon. The UK gallon is about 20% larger, so 10 UK gallons converted with 3.785 comes out at 37.85 L instead of the true 45.46 L, nearly 8 liters short. Check which gallon your source uses, especially with older documents and UK vehicle or recipe data.
Gallons to Liters Real-World Size Comparison Table
These are the gallon values people most often convert, from kitchen quantities to fuel tanks and drums.
| Gallons (gal) | Liters (L) | Real-World Size Benchmark |
|---|---|---|
| 0.25 gal | 0.95 L | One US quart |
| 0.5 gal | 1.89 L | A half-gallon carton of milk or juice |
| 1 gal | 3.785 L | One US gallon |
| 5 gal | 18.93 L | A 5-gallon bucket or water jug |
| 10 gal | 37.85 L | A 10-gallon aquarium or fuel container |
| 15 gal | 56.78 L | A typical car fuel tank (many are between 12 and 20 gallons) |
| 50 gal | 189.27 L | A typical residential water heater (often 40 to 50 gallons) |
| 55 gal | 208.2 L | A standard 55-gallon drum |
Where gallons-to-liters matters
This conversion matters most in three situations: comparing fuel prices, converting US recipes and container sizes, and buying equipment or containers across borders.
- • Use gal For: US fuel prices ($/gal), US recipe volumes (milk, stock), US gallon containers, US marine and RV fuel tanks
- • Use L For: Fuel prices per liter in most countries, Metric recipe volumes, Metric jerry cans and tanks, International fuel planning
Rule of Thumb: To compare fuel prices, divide the price per gallon by 3.785 to get the price per liter. If gas is $4 a gallon, that is about $1.06 per liter.
gal to L Converter in Spreadsheets — Spreadsheet Shortcut (Excel & Google Sheets)
For gallons to liters, use =A1*3.78541. For liters to gallons, use =A1/3.78541. The built-in =CONVERT(A1,"gal","l") converts US gallons in Excel. Use it to batch-convert a whole list without leaving the sheet.
Gallons to Liters Conversion — Frequently Asked Questions
How do I convert gallons to liters?
Multiply the number of US gallons by 3.78541. For example, 5 gallons × 3.78541 = 18.93 liters.
How many liters are in a gallon?
A US gallon is 3.785 liters. A UK (imperial) gallon is 4.546 liters.
Is 1 gallon the same as 4 liters?
No. One US gallon is 3.785 liters. Four liters is about 1.057 US gallons, slightly more than one gallon.
How many liters are in a 5-gallon bucket?
A 5-gallon bucket holds about 18.93 liters.
What is the difference between US and UK gallons?
A US gallon is 3.785 liters and a UK gallon is 4.546 liters, so the UK gallon is about 20% larger. Check which one your source uses.
How many liters are in a gallon of water?
One US gallon of water is 3.785 liters. The conversion is based on volume, so it is the same for any liquid.
How do I convert a fuel price per gallon to a price per liter?
Divide the price per gallon by 3.785. If the price is $4.00 per gallon, that is about $1.06 per liter.
Is it gallons to liters or gallons to litres?
Both are correct. Litres is the spelling in the UK, Ireland, Australia and most other countries, and liters is American. The conversion is identical.
gal to L Quick-Reference Conversion Table
The conversions you will use most often, including the reverse calculation.
| To convert | Operation | Example |
|---|---|---|
| gal → L | × 3.78541 | 5 gal → 18.93 L |
| L → gal | × 0.264172 | 10 L → 2.64 gal |
| UK gal → L | × 4.54609 | 10 UK gal → 45.46 L |
| gal → fl oz | × 128 | 1 gal → 128 fl oz |