Imperial Gallons to US Gallons

1 Imperial Gallon equals 1.20095 US Gallons using fixed marine unit definitions for the active route.

Direct Answer

1 Imperial Gallon equals 1.20095 US Gallons

This conversion uses fixed marine unit definitions for the active route.

For 2 Imperial Gallon, the result equals 2.4019 US Gallons.

Converter Calculator

1.20095 US Gallons (US gal)

Switch

Explanation

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.

Method & Reference

  • Method basis: exact conversion formula shown in Direct Answer.
  • Applied factor: 1 Imperial Gallon = 1.20095 US Gallons.
  • Consistency rule: calculator output and table values use the same constants and rounding policy.

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 convert in the opposite direction with the same fixed marine relationship.

Can I use decimal imperial gallons values?

Yes. Decimal imperial gallons values are supported, so navigation, depth, speed, and capacity calculations can stay precise.