Gallons ↔ Liters Converter
Convert between gallons (gal) and liters (L) instantly — both ways. Type in either box and the other updates live, with bonus conversions to milliliters, fluid ounces, cubic meters and more. Supports US and Imperial (UK) gallons.
Type a value in either box — the other converts automatically.
Which gallon standard drives the main conversion.
Controls how the converted values are rounded.
| Unit | Value |
|---|---|
| Convert to see all units | |
How to use the gallons to liters converter
Type into either box and the other updates as you go — gallons to liters or liters back to gallons, with a switch for US or imperial gallons, plus milliliters, fluid ounces, quarts, and a report you can download.
Pick the gallon type first
US or imperial. This changes the answer by about 20%, so set it before you read anything else.
Type into either box
Enter gallons or liters — whichever you have. The other converts live, no submit needed.
Check the equivalents
See the volume in water bottles, milk jugs, and bathtubs — a quick sanity check on the number.
Read all units & save a PDF
Ten conversions including both gallon standards, the bottle diagram, and a report you can keep.
How the conversion is calculated
There are two gallons in common use and they are not close. A US gallon is exactly 3.785412 liters; an imperial gallon is exactly 4.54609 liters. Everything on this page depends on knowing which one you have.
Worked example — a 50 liter fill-up
As US gallons: 50 ÷ 3.785412 = 13.21 gal
As imperial gallons: 50 ÷ 4.54609 = 11.00 gal
The gap: 13.21 − 11.00 = 2.21 gallons
As US fluid ounces: 50 × 33.814 = 1,690.7 fl oz
Same fuel, two answers 20% apart — which is exactly why the gallon type matters.
Gallons and liters conversion charts
The lookups that come up most — the conversion both ways, the two gallons side by side, the fuel economy figures that trip everyone up, and the container sizes worth knowing.
| US gallons | Liters | Milliliters | US fluid ounces |
|---|---|---|---|
| 1 gal | 3.785 L | 3,785 mL | 128 fl oz |
| 2 gal | 7.571 L | 7,571 mL | 256 fl oz |
| 3 gal | 11.356 L | 11,356 mL | 384 fl oz |
| 5 gal | 18.927 L | 18,927 mL | 640 fl oz |
| 10 gal | 37.854 L | 37,854 mL | 1,280 fl oz |
| 15 gal | 56.781 L | 56,781 mL | 1,920 fl oz |
| 20 gal | 75.708 L | 75,708 mL | 2,560 fl oz |
| 50 gal | 189.271 L | 189,271 mL | 6,400 fl oz |
| 100 gal | 378.541 L | 378,541 mL | 12,800 fl oz |
The fluid ounce column is exact: a US gallon is defined as 128 US fluid ounces, so every row is a clean multiple.
| Liters | US gallons | Imperial gallons | US quarts |
|---|---|---|---|
| 1 L | 0.264 gal | 0.220 gal | 1.057 qt |
| 5 L | 1.321 gal | 1.100 gal | 5.283 qt |
| 10 L | 2.642 gal | 2.200 gal | 10.567 qt |
| 20 L | 5.283 gal | 4.399 gal | 21.134 qt |
| 25 L | 6.604 gal | 5.499 gal | 26.417 qt |
| 50 L | 13.209 gal | 10.998 gal | 52.834 qt |
| 100 L | 26.417 gal | 21.997 gal | 105.669 qt |
| 200 L | 52.834 gal | 43.994 gal | 211.338 qt |
Two figures worth remembering: 50 liters is almost exactly 11 imperial gallons, and 20 liters — the standard jerry can — sits just above 5 US gallons.
| Measure | US gallon | Imperial (UK) gallon |
|---|---|---|
| Liters | 3.785412 L | 4.54609 L |
| Cubic inches | 231 in³ | 277.42 in³ |
| Cubic feet | 0.13368 ft³ | 0.16054 ft³ |
| Fluid ounces | 128 US fl oz | 160 imp fl oz |
| Quarts | 4 US qt | 4 imp qt |
| Pints | 8 US pt (473 mL each) | 8 imp pt (568 mL each) |
| Relative size | 1.000 | 1.20095 × larger |
Both gallons split into 4 quarts and 8 pints — the subdivisions match, the underlying sizes don’t. An imperial pint is 568 mL against the US pint’s 473 mL, which is why a UK pint of beer is visibly bigger.
| US MPG | UK MPG | Liters / 100 km | Km / liter |
|---|---|---|---|
| 20 mpg | 24.0 mpg | 11.76 L | 8.5 km |
| 25 mpg | 30.0 mpg | 9.41 L | 10.6 km |
| 30 mpg | 36.0 mpg | 7.84 L | 12.8 km |
| 35 mpg | 42.0 mpg | 6.72 L | 14.9 km |
| 40 mpg | 48.0 mpg | 5.88 L | 17.0 km |
| 50 mpg | 60.0 mpg | 4.70 L | 21.3 km |
Every row describes the same car. UK MPG looks 20% better purely because the imperial gallon is larger — nothing about the vehicle changes. Liters per 100 km is the neutral basis for comparing across markets.
| Item | US gallons | Liters | Metric equivalent sold |
|---|---|---|---|
| Milk jug | 1 gal | 3.785 L | 4 L jug |
| Paint can | 1 gal | 3.785 L | 4 L or 5 L tin |
| Bucket / pail | 5 gal | 18.927 L | 20 L pail |
| Jerry can | 5.28 gal | 20 L | 20 L standard |
| Compact car tank | ≈ 12 gal | ≈ 45.4 L | 45–50 L |
| Sedan tank | ≈ 15 gal | ≈ 56.8 L | 55–60 L |
| SUV / pickup tank | ≈ 26 gal | ≈ 98.4 L | 95–100 L |
| Water heater | 50 gal | 189.3 L | 190–200 L |
Metric equivalents are the nearest standard size, not exact conversions. A 4 litre paint tin holds about 5.7% more than a US gallon, which matters when you are matching coverage figures on a spec sheet.
The US kept the old English wine gallon of 231 cubic inches. Britain scrapped its assorted gallons in 1824 and defined a new imperial gallon, originally the volume of ten pounds of water. Two units, one name, 20% apart.
- Nothing on the label tells you which — both are written “gallon”. Source, not wording, is the clue: US spec or UK spec.
- The gap flatters UK fuel figures — a 30 US MPG car reads as 36 UK MPG. Same car, same fuel, bigger gallon.
- The liter is the neutral ground — both gallons are now defined exactly in liters, so converting to metric first removes all ambiguity.
Everything the converter works out
One figure in either box gives you the full picture — both gallon standards, the same volume in every unit, a scale you can picture, and a report you can keep.
The figures behind every gallon
Built for anyone caught between two systems
Most of the world buys liquid by the liter, the US buys it by the gallon, and the UK uses a gallon of an entirely different size — so this conversion turns up constantly.
Filling a rental car abroad, comparing a UK MPG figure against a US one, or working out what a per-liter pump price actually means per gallon.
- Convert to L/100 km to compare fairly
- UK MPG ≈ US MPG × 1.2
- Check the tank size in the manual
Following a metric recipe with US measuring cups, or matching a paint, sealant, or cleaner quoted in liters against gallon-sized tins on the shelf.
- A 4 L tin isn’t a US gallon
- US cup 237 mL vs metric cup 250 mL
- Compare coverage, not tin size
Checking tank, pump, or appliance capacity where the manufacturer is metric and the local listing is in gallons — or the reverse.
- Confirm which gallon the spec means
- Watch for rounded marketing sizes
- Save the PDF against the order
7 tips for converting gallons without errors
The slips that quietly throw a volume off by a fifth — and the checks that catch them.
Gallons to liters FAQ
The conversion, fuel, and capacity questions people ask most when a volume is quoted in the unit they don’t use.
It depends which gallon. A US gallon is exactly 3.785411784 liters, while an imperial or UK gallon is exactly 4.54609 liters.
The imperial gallon is about 20 percent larger, so the two are never interchangeable. Both figures are exact definitions rather than rounded measurements, which is why the converter offers a gallon-type switch.
Multiply US gallons by 3.785412, or imperial gallons by 4.54609. A 15 US gallon fuel tank comes to 15 × 3.785412 = 56.78 L.
To go the other way, divide liters by the same factor — or multiply liters by 0.264172 for US gallons and 0.219969 for imperial gallons.
They were standardised separately. The United States kept the old English wine gallon, fixed at 231 in³. Britain replaced its various gallons in 1824 with a new imperial gallon, originally defined as the volume of ten pounds of water.
That left two units sharing one name. An imperial gallon is 277.42 in³ against the US gallon’s 231 — roughly 20 percent larger — and today both are defined exactly in liters.
Five US gallons is about 18.93 liters, which is why the standard US bucket is often sold as a 20 litre pail in metric markets. Five imperial gallons is about 22.73 L.
The common metric jerry can is 20 litres, sitting between the two — slightly more than 5 US gallons and slightly less than 5 imperial gallons.
No, and the gap is significant. Because an imperial gallon is about 20 percent larger, the same car returns a UK MPG figure roughly 1.2 times its US MPG figure without being any more efficient.
A car rated at 30 US MPG is about 36 UK MPG, or 7.84 liters per 100 km. When comparing fuel economy across markets, convert everything to liters per 100 km first.
A US gallon holds 128 US fluid ounces. An imperial gallon holds 160 imperial fluid ounces.
The ounces themselves also differ: a US fluid ounce is about 29.57 mL while an imperial fluid ounce is about 28.41 mL. So the imperial gallon holds both more ounces and slightly smaller ones.
One liter is about 0.264172 US gallons, or 0.219969 imperial gallons. Put another way, it takes just under four liters to make a US gallon and just over four and a half to make an imperial one.
A handy anchor for fuel: 50 liters is very close to exactly 11 imperial gallons, and about 13.21 US gallons.
Typical ranges are 45–55 liters for a compact car, 55–65 for a mid-size sedan, and 70–100 for an SUV or pickup. In US gallons that’s roughly 12–15, 15–17, and 18–26.
These are usable capacities and vary widely by model. Check the owner’s manual for the exact figure, and remember the fuel gauge usually reaches empty with a reserve still in the tank.
Planning Estimate Only — Check Which Gallon Applies: This converter changes the volume you enter between gallons and liters using exact conversion factors, and the result depends entirely on whether the US gallon (3.785412 L) or the imperial gallon (4.54609 L) is selected. Confirm which standard your source uses before relying on any figure. Fuel tank sizes, container capacities, and metric equivalents shown on this page are typical published values that vary by model and manufacturer; usable capacity is normally lower than nominal capacity. Fuel economy figures are direct unit conversions and do not account for test cycle differences between markets, which can change published ratings independently of the gallon used. For planning purposes only.