Imperial Gallons to US Gallons
Snapshot
1 Imperial Gallon equals 1.20095 US Gallons. Conversion Encyclopedia uses the same fixed conversion basis across the calculator, common values, and reverse page for this page.
- Reference basis: This result uses fixed marine-capacity definitions for tanks, holds, and onboard volume checks.
- Example: For 2 Imperial Gallon, the result equals 2.4019 US Gallons.
- Use the reverse page if you need the opposite direction with the same basis.
Use the interactive calculator below for custom values and the common-value table for quick checks.
Converter Calculator
1.20095 US Gallons (US gal)
SwitchExplanation
Formula: US Gallons = Imperial Gallon × 1.20095. Why: tank and hold-capacity units are tied to fixed volume definitions, so the route normalizes through one volumetric basis before applying the target unit.
Imperial Gallons (Imp gal): a UK imperial liquid-volume unit used in some marine and fuel-capacity references.
US Gallons (US gal): a US customary liquid-volume unit used for fuel, tanks, and onboard capacity references in US-based contexts.
This route is useful when translating tank, hold, and onboard liquid-capacity values across metric and gallon-based systems for storage, fueling, and vessel operations.
This conversion is purely multiplicative because both units reduce through one fixed marine reference basis for the active family, with no offset.
Common Conversion Values
| Imperial Gallon (Imp gal) | US Gallons (US gal) |
|---|---|
| 1 | 1.20095 |
| 2 | 2.4019 |
| 5 | 6.00475 |
| 10 | 12.009499 |
| 20 | 24.018999 |
| 50 | 60.047496 |
| 100 | 120.094993 |
Frequently Asked Questions
How many us gallons are in 1 imperial gallon?
This route uses a fixed factor, so 1 imperial gallon equals 1.2009499255 us gallons.
What is the reverse conversion for Imperial Gallons to US Gallons?
Use the US Gallons to Imperial Gallons page to reverse the same tank or hold-capacity relationship for onboard volume checks.
Can I use decimal imperial gallons values?
Yes. Decimal imperial gallons values are supported for fueling, storage, and onboard capacity checks.