Gallon (Imperial) to Gallon (US) Converter
1 Gallon (Imperial) is equal to 1.20095Gallon (US)s (gal). To convert gallon (imperial)s to gallon (us)s, multiply the value by 1.20095 or use the interactive formula breakdown and reference tables below.
Volume Converter
-- Step-by-Step Mathematical Derivation
To convert any quantity from Gallon (Imperial) to Gallon (US), multiply the quantity by the constant conversion factor 1.20095.
To reverse the operation, multiply your Gallon (US) figure by 0.8326742 (or divide by 1.20095).
- Identify the starting value in Gallon (Imperial) (imp gal).
- Apply the exact linear conversion factor:
1 imp gal = 1.20095 gal. - Multiply the input value by 1.20095 to obtain the exact measurement in Gallon (US) (gal).
- Verify precision against standard BIPM / NIST SP 811 statutory guidelines.
All-Units Instant Matrix
Printable Reference Cheat Sheet
Generate clean offline reference PDF tables for Volume & Liquid
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Academic & Research Citation Exporter
Cite this mathematical formula and conversion factor in research papers and wikis
@misc{ai_unit_converter_gallon_(imperial)_to_gallon_(us),
author = {AI Unit Converters Standards Board},
title = {Exact Gallon (Imperial) to Gallon (US) Conversion Factor and Mathematical Derivation},
year = {2026},
howpublished = {\url{https://aiunitconverters.com/volume/gal_uk-to-gal_us}},
note = {Derived from NIST Special Publication 811 and BIPM SI Brochure}
}📊Gallon (Imperial) to Gallon (US) Conversion Tables
| 1imp gal | 1.2009gal |
| 2imp gal | 2.4019gal |
| 5imp gal | 6.0047gal |
| 10imp gal | 12.0095gal |
| 15imp gal | 18.0142gal |
| 20imp gal | 24.019gal |
| 25imp gal | 30.0237gal |
| 50imp gal | 60.0475gal |
| 75imp gal | 90.0712gal |
| 100imp gal | 120.095gal |
| 250imp gal | 300.2375gal |
| 500imp gal | 600.475gal |
| 1000imp gal | 1,200.9499gal |
| 5000imp gal | 6,004.7496gal |
| 10000imp gal | 12,009.4993gal |
| 1gal | 0.8327imp gal |
| 2gal | 1.6653imp gal |
| 5gal | 4.1634imp gal |
| 10gal | 8.3267imp gal |
| 15gal | 12.4901imp gal |
| 20gal | 16.6535imp gal |
| 25gal | 20.8169imp gal |
| 50gal | 41.6337imp gal |
| 75gal | 62.4506imp gal |
| 100gal | 83.2674imp gal |
| 250gal | 208.1685imp gal |
| 500gal | 416.3371imp gal |
| 1000gal | 832.6742imp gal |
| 5000gal | 4,163.3709imp gal |
| 10000gal | 8,326.7418imp gal |
❓ Frequently Asked Questions: Gallon (Imperial) to Gallon (US)
How do you convert Gallon (Imperial)s to Gallon (US)s?▼
1 Gallon (Imperial) is equal to 1.20095 Gallon (US)s. Multiply your input value in Gallon (Imperial)s by 1.20095 to obtain the exact equivalent in Gallon (US)s.
How many Gallon (US)s are in 1 Gallon (Imperial)?▼
There are exactly 1.20095Gallon (US)s (gal) in 1 Gallon (Imperial) (imp gal).
Are these calculations calibrated against official measurement standards?▼
Yes. All conversion factors on AI Unit Converters are calibrated and cross-verified against official BIPM SI Brochure (9th Edition), NIST SP 811, and ISO 80000 measurement metrology standards.