Understanding Imperial Gallons per Day to Imperial Gallons per Hour Conversion
The Imperial Gallon per Day (imp-gal/d) is a volume flow rate equal to one UK gallon of 4.54609 litres flowing steadily over a 24-hour day, a rate often used for water usage, irrigation and metering in Commonwealth countries. The Imperial Gallon per Hour (imp-gal/h) is an Imperial flow rate of one UK gallon (4.54609 litres) each hour. Converting between them lets you compare a slow daily consumption figure against a faster time base or a different measurement system. Both units use the Imperial gallon, so this is purely a per-day to per-hour rescaling by a factor of 24.
Conversion Formula
To convert Imperial Gallons per Day to Imperial Gallons per Hour, multiply the number of Imperial Gallons per Day by this factor:
Step-by-Step Example
Convert 25 Imperial Gallons per Day to Imperial Gallons per Hour.
Write the formula:
Substitute the value:
Calculate the result:
How to Convert Imperial Gallons per Day to Imperial Gallons per Hour
Follow these steps to change a flow rate from Imperial Gallons per Day into Imperial Gallons per Hour.
- Identify the value: Note the flow rate you have in Imperial Gallons per Day (imp-gal/d).
- Apply the factor: Multiply that number by 0.0416667, the number of Imperial Gallons per Hour in one Imperial Gallon per Day.
- Read the result: The product is your flow rate in Imperial Gallons per Hour (imp-gal/h).
- Check with an example: 25 imp-gal/d × 0.0416667 ≈ 1.04167 imp-gal/h.
Imperial Gallons per Day to Imperial Gallons per Hour conversion table
| Imperial Gallons per Day (imp-gal/d) | Imperial Gallons per Hour (imp-gal/h) |
|---|---|
| 0 | 0 |
| 1 | 0.04166667 |
| 2 | 0.08333333 |
| 3 | 0.125 |
| 4 | 0.1666667 |
| 5 | 0.2083333 |
| 6 | 0.25 |
| 7 | 0.2916667 |
| 8 | 0.3333333 |
| 9 | 0.375 |
| 10 | 0.4166667 |
| 15 | 0.625 |
| 20 | 0.8333333 |
| 25 | 1.041667 |
| 30 | 1.25 |
| 40 | 1.666667 |
| 50 | 2.083333 |
| 60 | 2.5 |
| 70 | 2.916667 |
| 80 | 3.333333 |
| 90 | 3.75 |
| 100 | 4.166667 |
| 150 | 6.25 |
| 200 | 8.333333 |
| 250 | 10.41667 |
| 300 | 12.5 |
| 400 | 16.66667 |
| 500 | 20.83333 |
| 600 | 25 |
| 700 | 29.16667 |
| 800 | 33.33333 |
| 900 | 37.5 |
| 1000 | 41.66667 |
| 2000 | 83.33333 |
| 3000 | 125 |
| 4000 | 166.6667 |
| 5000 | 208.3333 |
| 10000 | 416.6667 |
| 25000 | 1041.667 |
| 50000 | 2083.333 |
| 100000 | 4166.667 |
| 250000 | 10416.67 |
| 500000 | 20833.33 |
| 1000000 | 41666.67 |
What is the Imperial Gallon per Day?
The Imperial gallon per day (imp gal/d) is a unit of volumetric flow rate that expresses how many Imperial gallons of a fluid pass a point over the span of one day. It is used in the UK and Commonwealth countries for water supply, well yields, plumbing, and utility metering.
Definition
One Imperial gallon per day equals one Imperial gallon of volume divided by the 86,400 seconds in a day. Expressed in SI units of litres per second:
This follows directly from the exact definitions: an Imperial gallon = 4.54609 L exactly, and one day = 86,400 s, so L/s.
Origin and History
The Imperial gallon was fixed by the British Weights and Measures Act of 1824, originally as the volume of 10 pounds of distilled water. It was later redefined in metric terms and, since 1985, has been exactly 4.54609 litres. Expressing flow "per day" arose naturally from water-utility billing and reservoir management, where daily throughput is the practical accounting period.
Law and Notable Facts
The Imperial gallon remains a legally recognised unit in the United Kingdom and several Commonwealth nations, distinct from the smaller US gallon (3.785411784 L exactly). Because of this, an Imperial gallon per day is about 20% larger than a US gallon per day (1 imp gal/d ≈ 1.20095 US gal/d), a difference that matters when reading equipment specified in the other system.
Real-World Examples and Conversions
- A typical UK household uses on the order of 100 Imperial gallons per day (about 455 litres), which is roughly 0.00526 L/s.
- A small trickling borehole yielding 1,000 imp gal/d supplies about 4,546 litres daily, or roughly 0.0526 L/s.
- Converting to metric daily volume: 1 imp gal/d = 4.54609 litres per day.
- 1,000,000 imp gal/d (a common water-treatment plant rating) equals about 52.6 L/s, or roughly 4.546 megalitres per day.
What is the Imperial Gallon per Hour?
The imperial gallon per hour (imp-gal/h) is a unit of volumetric flow rate expressing how many imperial gallons of fluid pass a point in one hour. It is used in the UK and other Commonwealth countries for pumps, fuel consumption, and plumbing flow ratings.
Definition
One imperial gallon per hour equals one imperial gallon of volume divided by one hour (3,600 seconds):
The imperial gallon is defined as exactly 4.54609 litres, so dividing by 3,600 seconds gives 4.54609 / 3600 = 0.00126280 L/s (equivalently 4.54609 L/h).
Origin and History
The imperial gallon was established by the British Weights and Measures Act of 1824, originally defined as the volume of 10 pounds of water at a specified temperature. It was later fixed by reference to the litre. The "per hour" rate arose naturally in the 19th and 20th centuries as a practical measure for pump throughput and fuel usage, hours being a convenient interval for slow, steady flows.
Law and Notable Facts
The imperial gallon (4.54609 L exactly) is legally distinct from and about 20% larger than the US liquid gallon of 3.785411784 L. As a result an imperial gallon per hour is likewise about 20% greater than a US gallon per hour. Since UK metrication, the imperial gallon is no longer a primary trade unit but persists in fuel-economy figures (miles per gallon) and equipment specifications.
Real-World Examples and Conversions
- A small garden or aquarium pump rated at 100 imp-gal/h moves about 454.6 litres of water every hour, roughly 0.126 L/s.
- A domestic tap running at 1 imperial gallon per hour is a bare trickle of about 4.55 L each hour.
- 1 imp-gal/h ≈ 0.833 US gal/h, reflecting the larger imperial gallon.
- A pump moving 220 imp-gal/h delivers about 1,000 L/h, or roughly 0.278 L/s.
Frequently Asked Questions
What is the formula to convert Imperial Gallons per Day to Imperial Gallons per Hour?
Multiply the flow rate in imp-gal/d by 0.0416667 to get the value in imp-gal/h. In symbols, imp-gal/h = imp-gal/d × 0.0416667.
How many Imperial Gallons per Hour are in 1 Imperial Gallon per Day?
One Imperial Gallon per Day equals 0.0416667 Imperial Gallons per Hour. Conversely, one Imperial Gallon per Hour equals 24 Imperial Gallons per Day.
How do I convert 10 Imperial Gallons per Day to Imperial Gallons per Hour?
Multiply 10 by 0.0416667, which gives 0.416667 imp-gal/h.
Does this use the UK or US gallon?
The source unit is the Imperial (UK) gallon of 4.54609 litres, not the US liquid gallon of 3.785412 litres. Both units use the Imperial gallon, so this is purely a per-day to per-hour rescaling by a factor of 24.
Where is the Imperial Gallon per Day used in practice?
It is common in water-supply metering, plumbing, irrigation and appliance flow ratings in the UK and other Commonwealth regions, where daily consumption is the natural reporting period.