Convert Liters to UK Gallons – Volume Converter
This converter converts a volume expressed in litres (L) to UK (imperial) gallons. The conversion uses the officially defined relationship between the two units so the arithmetic result is deterministic and reproducible.
While the mathematical conversion is exact given the defined factor, real-world measurement uncertainty depends on how the litre value was obtained (measuring device resolution, temperature effects, calibration). Use calibrated instruments and follow applicable measurement standards when results are used for regulatory reporting, trade, or safety-critical calculations.
This page includes the conversion formula, worked examples, short guidance on rounding and uncertainty, and pointers to relevant standards for laboratories and regulated environments.
Interactive Converter
Convert between liter and uk gallon with precision rounding.
Quick reference table
| Liter | UK Gallon |
|---|---|
| 1 L | 0.22 UK gal |
| 5 L | 1.0998 UK gal |
| 10 L | 2.1997 UK gal |
| 25 L | 5.4992 UK gal |
| 50 L | 10.9985 UK gal |
| 100 L | 21.9969 UK gal |
Methodology
The converter applies a fixed conversion factor between volume units. By international and national definitions, one UK (imperial) gallon equals 4.54609 litres. The conversion calculation therefore divides the litre quantity by 4.54609.
Because the conversion factor is a defined constant, the numerical conversion itself does not introduce measurement uncertainty. Total uncertainty arises from the original volume measurement, including instrument accuracy, environmental conditions, and repeatability.
For regulated testing and calibration, follow recognized standards such as NIST guidance on units and ISO/IEC 17025 for laboratory competence. Maintain calibrated equipment traceable to national metrology institutes and record uncertainty where required.
Worked examples
Example 1: Convert 10 litres to UK gallons → 10 ÷ 4.54609 = 2.199689 (approx 2.1997 UK gallons).
Example 2: Convert 50 litres to UK gallons → 50 ÷ 4.54609 = 10.998446 (approx 10.9984 UK gallons).
Further resources
External guidance
Expert Q&A
Is the conversion factor exact or approximate?
The factor 1 UK gallon = 4.54609 litres is the defined relationship used for conversion. The arithmetic conversion using that factor is exact. Measurement uncertainty arises from how the litre measurement was obtained.
How is this different from US gallons?
US liquid gallons use a different size (1 US gallon = 3.785411784 litres). Always confirm whether a calculation or specification requires UK (imperial) or US gallons before converting.
How many decimal places should I show?
For casual or everyday use 2 decimal places are often sufficient. For technical, legal, or trade reporting follow the precision required by your contract, lab standard, or regulatory authority. Laboratories typically document and report uncertainty alongside numeric results.
Can I convert negative values or extremely large volumes?
The mathematical conversion supports any numeric input. Negative volumes are physically meaningful only in specific contexts (e.g., flow direction, bookkeeping). For extremely large values, ensure your application handles large floats and uses appropriate units for readability (e.g., cubic metres, megalitres).
What about temperature and density effects?
Volume measurements can change with temperature. The conversion between litres and gallons is unit-to-unit and does not correct for thermal expansion or density. For precision work, measure or correct volumes at a defined reference temperature per relevant standards.
Sources & citations
- NIST Guide to the SI (Special Publication and guidance on units) — https://www.nist.gov/publications/guide-use-international-system-units-si
- ISO/IEC 17025 — General requirements for the competence of testing and calibration laboratories — https://www.iso.org/standard/66912.html
- National Physical Laboratory (UK) — National metrology authority — https://www.npl.co.uk/
- Occupational Safety and Health Administration (OSHA) — https://www.osha.gov/