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US gallons to Imperial gallons (gal (US) to gal (UK))

Convert US gallons to imperial gallons: 1 gal (US) = 0.832674 gal (UK). Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

Formula

1 gal (US) = 0.832674 gal (UK)

imperial gallons = US gallons × 0.8326741846 — reverse: US gallons = imperial gallons × 1.200949926

The factor is derived from the SI definitions of both units (base unit: L) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.

Worked examples

US gallons to imperial gallons conversion table

US gallons (gal (US))Imperial gallons (gal (UK))
10.832674
21.66535
32.49802
43.3307
54.16337
64.99605
75.82872
86.66139
97.49407
108.32674
1512.4901
2016.6535
2520.8169
3024.9802
4033.307
5041.6337
7562.4506
10083.2674
200166.535
250208.169
500416.337
1000832.674

FAQ

How many imperial gallons are in one gallon?

1 gal (US) = 0.832674 gal (UK). The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

What is the formula to convert US gallons to imperial gallons?

Multiply the value in US gallons by 0.8326741846: imperial gallons = US gallons × 0.8326741846. For example, 5 gal (US) = 4.16337 gal (UK).

How do I convert imperial gallons back to US gallons?

Multiply by the inverse factor 1.200949926 (US gallons = imperial gallons × 1.200949926), or use the imperial gallons-to-US gallons page.

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