Convert Imperial Gallons to Acre-Feet

Convert Imperial Gallons (UK gal) to Acre-Feet (ac ft) instantly and accurately.

Imperial Gallons (UK gal)
Acre-Feet (ac ft)

Conversion Formula

ac ft = UK gal × 3.685575143e-6

About Imperial Gallons

A US imperial gallon (UK gal) = exactly 8 imperial pints or 10 lb of pure water at 62°F ≈ 4.546 L - about 20% larger than the US liquid gallon (3.785 L). The weight-based definition made it verifiable with simple scales. Still the legal fuel measure in the Cayman Islands and other British Overseas Territories. UK mpg ratings use imperial gallons: 50 UK mpg ≈ 42 US mpg. 1 UK gal ≈ 4.546 L.

About Acre-Feet

An acre-foot (ac ft) = the volume covering 1 acre to 1 ft depth ≈ 1,233.5 m³ (325,851 US gal). Almost exclusively used in US water resource management. California's Lake Shasta: 4.55 million ac ft at capacity. A typical US household uses ~0.5-1 ac ft/year. Water rights on the Colorado and Sacramento rivers are traded in acre-feet. 1 ac ft ≈ 1,233.5 m³.

Quick Reference Table

Imperial Gallons (UK gal)Acre-Feet (ac ft)
1 UK gal3.686 × 10-6 ac ft
2 UK gal7.371 × 10-6 ac ft
5 UK gal1.843 × 10-5 ac ft
10 UK gal3.686 × 10-5 ac ft
25 UK gal9.214 × 10-5 ac ft
50 UK gal0.000184279 ac ft
100 UK gal0.000368558 ac ft

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