Volume · Unit Converter

Convert Acre-Foot to Imperial Gallon

Convert acre-feet to imperial gallons instantly. 1 acre-foot = 271328.0725959055 imperial gallon — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Imperial Gallon to Acre-Foot converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Jaya Christiyan K G, Ph.D.
Volume category 2 min read Published Last reviewed Updated

Units explained

Industrial / Specialized

Acre-Foot

What is a acre-foot?

An acre-foot is the volume covering one acre to a depth of one foot (1,233.48 m³).

Origin of the acre-foot

Combines the acre and the foot for large water volumes.

Where it is used

The standard US unit for reservoir and irrigation water.

When and where it was developed

US water management.

Imperial (UK)

Imperial Gallon

What is a imperial gallon?

The imperial gallon is defined as exactly 4.54609 liters.

Origin of the imperial gallon

Set by the British Weights and Measures Act of 1824 as the volume of 10 lb of water.

Where it is used

Used for fuel and beverages in the UK and Commonwealth.

When and where it was developed

UK, 1824.

Acre-Foot to Imperial Gallon conversion formula

The relationship between acre-feet and imperial gallons:

1 ac·ft = 271328.0725959055 gal
1 gal = 3.685575e-6 ac·ft

To convert acre-feet to imperial gallons, multiply the value in acre-feet by 271328.0725959055. To reverse, multiply imperial gallons by 3.685575e-6.

How to use this converter

Type a value into the calculator. The result in imperial gallons updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Imperial Gallon to Acre-Foot converter for the reverse direction.

Step-by-step: convert acre-feet to imperial gallons

  1. Write down the value in acre-feet (ac·ft).
  2. Multiply that value by the factor 271328.0725959055.
  3. The product is the equivalent value in imperial gallons (gal).
  4. To reverse, multiply the imperial gallon value by 3.685575e-6.

Worked examples

Example 1 — Convert 1 ac·ft to gal:
1 × 271328.0725959055 = 271328.0725959055 gal

Example 2 — Convert 100 ac·ft to gal:
100 × 271328.0725959055 = 2.713281e+7 gal

Real-world example — Geographic to architectural conversion

One acre-foot equals 100,000 imperial gallons. The conversion bridges geographic-scale survey work and architectural-scale building plans on the same drawing.

1 ac·ft × 271328.0725959055 = 271328.0725959055 gal

Real-world example — Geographic to architectural scale

One acre-foot equals 100,000 imperial gallons. Map scales use this when an architectural site plan (in the smaller unit) must be related to road-network plans (in the larger unit) on the same drawing.

1 ac·ft × 271328.0725959055 = 271328.0725959055 gal

Acre-Foot to Imperial Gallon conversion table

Standard reference values for converting acre-feet to imperial gallons:

Acre-Foot [ac·ft]Imperial Gallon [gal]
0.012713.2807259591
0.127132.8072595905
1271328.0725959055
2542656.1451918109
3813984.2177877163
41085312.2903836218
51356640.3629795273
102713280.7259590547
205426561.4519181093
308139842.1778771635
401.085312e+7
501.35664e+7
1002.713281e+7
5001.35664e+8
10002.713281e+8

Frequently asked questions

How many imperial gallons is 1 acre-foot?
1 acre-foot equals 271328.0725959055 imperial gallon.
How do I convert acre-feet to imperial gallons?
Multiply the value in acre-feet by 271328.0725959055 to get imperial gallons.
How do I convert imperial gallons back to acre-feet?
Multiply the value in imperial gallons by 3.685575e-6, or use the Imperial Gallon to Acre-Foot converter.
How many imperial gallons is 100 acre-feet?
100 acre-feet equals 2.713281e+7 imperial gallons, because 100 × 271328.0725959055 = 2.713281e+7.

Convert Acre-Foot to other volume units

Show all Acre-Foot conversions
Metric / SI (3 units)
Acre-Foot to Milliliter (mL) Acre-Foot to Liter (L) Acre-Foot to Cubic Meter (m³)
US Customary (Liquid) (1 units)
Acre-Foot to US Gallon (gal)
Imperial (UK) (1 units)
Acre-Foot to Imperial Gallon (gal)
Cubic (length-derived) (1 units)
Acre-Foot to Cubic Foot (ft³)

Sources & references

Conversion factor (1 ac·ft = 271328.0725959055 gal) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.