UK Gallons to Liters
Convert any value from us gallon to liter with full precision. Use the converter above for instant results, or read on for the exact formula, worked examples, common uses, and answers to frequently asked questions.
📊 Quick Conversion Table
About the US Gallon to Liter conversion
Volume conversions handle liquids, gases, and the capacity of containers. The metric system uses liters and milliliters, while the US customary system uses fluid ounces, cups, pints, quarts, and gallons. The UK uses a different gallon than the US, which is a frequent source of confusion in recipes and fuel calculations.
This page focuses specifically on converting us gallon to liter. Use the converter above for instant results, or read on for the exact formula, a worked example, and answers to common questions.
Where this conversion is used
Cooks follow recipes that mix metric and US measurements. Drivers in Canada, the UK, and other countries compare fuel efficiency in liters per 100 km while US drivers use miles per gallon. Bartenders and baristas measure in fluid ounces, milliliters, and shots. Scientists use cubic centimeters (milliliters) and cubic meters for precise work.
If you frequently convert us gallon to liter, bookmark this page — the exact URL gives you instant access without searching, and the conversion widget is ready to use the moment the page loads.
Conversion formula
The exact mathematical relationship between us gallon and liter is:
1 us gallon = 3.78541178 liter
So to convert a value V from us gallon to liter, use:
Vliter = Vus gallon × 3.78541178
To go in the opposite direction:
Vus gallon = Vliter × 0.26417205
These factors come from the international definitions published by NIST, BIPM, and ISO 80000 and are exact within their respective standard systems. The converter applies them with full floating-point precision.
Worked example
Using the formula above, here are some common values converted from US Gallon to Liter:
| US Gallon | Liter |
|---|---|
| 1 | 3.785412 |
| 5 | 18.927059 |
| 10 | 37.854118 |
| 25 | 94.635295 |
| 50 | 189.270589 |
| 100 | 378.541178 |
Sources and accuracy
The liter is defined as exactly 1,000 cubic centimeters, with the centimeter defined by the BIPM. The US liquid gallon equals exactly 3.785411784 L. The UK (imperial) gallon equals exactly 4.54609 L. These fixed values have been internationally standardized.
This page was reviewed against multiple authoritative references. Conversion factors are cross-checked with the NIST SP 811 guide, the BIPM SI brochure, ISO 80000, and where applicable, the historical references for older unit systems. If you spot an inconsistency or have a suggested improvement, please let us know via the contact page.
Important disclaimer: for mission-critical work — medical dosing, legal-for-trade measurements, aerospace, large-scale engineering, and financial calculations — always verify independently with the original source. This converter is intended for everyday conversions, education, and quick reference.
Practical tips
Never confuse US fluid ounces with UK fluid ounces — they differ by about 4%. The same applies to US and UK gallons and pints. When in doubt, the converter shows the exact factor used so you can verify the result.
If you are converting large lists of values, use the swap button to instantly reverse direction without retyping. For decimal-heavy values you can paste them directly into the From field — the input accepts standard decimal notation, including negative values and scientific notation (for example, 1.23e-5).
Frequently asked questions
How accurate is this us gallon to liter converter?
It uses the official international conversion factors from NIST and BIPM with full double-precision floating-point accuracy. For everyday use the result is precise to many more decimal places than any practical measurement requires.
Can I convert in both directions?
Yes. Use the ⇄ button above to swap the From and To fields. You can also change either dropdown to any unit in the volume category.
Do I need an internet connection?
Only for the first page load. Once the converter is loaded it runs entirely in your browser, so it works offline as well.
Is my data private?
Yes. The conversion calculation happens locally in your browser. The values you enter are never sent to any server.