Convert Imperial Gallons to Milliliters
1 imperial gallon (gal (imp)) equals 4546.09 milliliters (mL).
1 gal (imp) = 4546.09 mL
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk imperial gallon to milliliter converter to paste a column from Excel.
How to Convert Imperial Gallon to Milliliter
- 1 gal (imp) = 4546.09 mL
- 1 mL = 0.0002199692483 gal (imp)
- Example: convert 15 gal (imp) to mL: 15 gal (imp) = 15 × 4546.09 mL = 68191.35 mL
Formula
mL = gal (imp) × 4546.09
Derivation from SI units:
- 1 imp gal = 4.54609 L = 0.00454609 m³ (exact, by definition)
- 1 mL = 10⁻³ L = 1 cm³ = 10⁻⁶ m³
- 1 gal (imp) = 0.00454609 m³ ÷ 0.000001 m³ per mL = 4546.09 mL
Both units are defined exactly, so the factor is exact. Imperial Gallon definition: imperial gallon; Milliliter definition: milliliter.
Worked examples
- A reading of 5 gal (imp) converts to 22730.45 mL.
5 gal (imp) × 4546.09 = 22730.45 mL - A value of 25 gal (imp) is 113652.25 mL.
25 gal (imp) × 4546.09 = 113652.25 mL
Imperial Gallon to Milliliter conversion table
| Imperial Gallons (gal (imp)) | Milliliters (mL) |
|---|---|
| 0.25 gal (imp) | 1136.5225 mL |
| 0.5 gal (imp) | 2273.045 mL |
| 1 gal (imp) | 4546.09 mL |
| 2 gal (imp) | 9092.18 mL |
| 5 gal (imp) | 22730.45 mL |
| 10 gal (imp) | 45460.9 mL |
| 15 gal (imp) | 68191.35 mL |
| 20 gal (imp) | 90921.8 mL |
| 25 gal (imp) | 113652.25 mL |
| 40 gal (imp) | 181843.6 mL |
| 50 gal (imp) | 227304.5 mL |
| 100 gal (imp) | 454609 mL |
| 1000 gal (imp) | 4546090 mL |
Where it's used
Imperial Gallons are used for fuel economy in the UK (miles per gallon), while milliliters appear in medicine doses and syringes. Both measure volume (capacity), so the conversion is a fixed factor.
Imperial Gallon to other volume units
| Conversion | 1 gal (imp) equals |
|---|---|
| imperial gallon to cubic meter | 0.00454609 m³ |
| imperial gallon to liter | 4.54609 L |
| imperial gallon to milliliter | 4546.09 mL |
| imperial gallon to cubic centimeter | 4546.09 cm³ |
| imperial gallon to cubic foot | 0.1605436532 ft³ |
| imperial gallon to cubic inch | 277.4194328 in³ |
| imperial gallon to US gallon | 1.200949926 gal (US) |
Frequently asked questions
How many milliliters are in 1 imperial gallon?
1 gal (imp) = 4546.09 mL.
How do I convert imperial gallons to milliliters?
Multiply the value in gal (imp) by 4546.09. For example, 15 gal (imp) × 4546.09 = 68191.35 mL.
Is the gal (imp) to mL conversion exact?
Yes. Both units are defined exactly, and 1 gal (imp) is exactly 4546.09 mL.
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "gallon [Canadian and U.K. (Imperial)]".
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 8, litre with SI prefix milli.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Imperial Gallons to Milliliters. Retrieved October 17, 2026, from https://scientificconverters.com/volume/imperial-gallons-to-milliliters/
IEEE
Scientific Converters, "Convert Imperial Gallons to Milliliters," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/volume/imperial-gallons-to-milliliters/