Volume · Unit Converter

Convert Imperial Fluid Drachm to Imperial Gallon

Convert imperial fluid drachms to imperial gallons instantly. 1 imperial fluid drachm = 0.00078125 imperial gallon — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Imperial Gallon to Imperial Fluid Drachm 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

Imperial (UK)

Imperial Fluid Drachm

What is a imperial fluid drachm?

An imperial fluid drachm is 1/8 of an imperial fluid ounce (3.5516 mL).

Origin of the imperial fluid drachm

The British apothecaries' subdivision of the fluid ounce.

Where it is used

Historical pharmacy unit.

When and where it was developed

UK apothecaries' system.

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.

Imperial Fluid Drachm to Imperial Gallon conversion formula

The relationship between imperial fluid drachms and imperial gallons:

1 fl dr = 0.00078125 gal
1 gal = 1280 fl dr

To convert imperial fluid drachms to imperial gallons, multiply the value in imperial fluid drachms by 0.00078125. To reverse, multiply imperial gallons by 1280.

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 Imperial Fluid Drachm converter for the reverse direction.

Step-by-step: convert imperial fluid drachms to imperial gallons

  1. Write down the value in imperial fluid drachms (fl dr).
  2. Multiply that value by the factor 0.00078125.
  3. The product is the equivalent value in imperial gallons (gal).
  4. To reverse, multiply the imperial gallon value by 1280.

Worked examples

Example 1 — Convert 1 fl dr to gal:
1 × 0.00078125 = 0.00078125 gal

Example 2 — Convert 100 fl dr to gal:
100 × 0.00078125 = 0.078125 gal

Real-world example — Packaging gauge

A 4-imperial fluid drachm plastic bag thickness is a common spec for grocery and freezer bags. Converting from imperial fluid drachms to imperial gallons is what packaging buyers do whenever they bridge US and metric supplier quotes.

4 fl dr × 0.00078125 = 0.003125 gal

Real-world example — Plastic film and laminate thickness

A 500-imperial fluid drachm sheet is a typical spec for ID-card laminates and film overlays. Converting to imperial gallons aligns the value with the unit most CAD systems and material datasheets prefer.

500 fl dr × 0.00078125 = 0.390625 gal

Imperial Fluid Drachm to Imperial Gallon conversion table

Standard reference values for converting imperial fluid drachms to imperial gallons:

Imperial Fluid Drachm [fl dr]Imperial Gallon [gal]
0.017.8125e-6
0.17.8125e-5
10.00078125
20.0015625
30.00234375
40.003125
50.00390625
100.0078125
200.015625
300.0234375
400.03125
500.0390625
1000.078125
5000.390625
10000.78125

Frequently asked questions

How many imperial gallons is 1 imperial fluid drachm?
1 imperial fluid drachm equals 0.00078125 imperial gallon.
How do I convert imperial fluid drachms to imperial gallons?
Multiply the value in imperial fluid drachms by 0.00078125 to get imperial gallons.
How do I convert imperial gallons back to imperial fluid drachms?
Multiply the value in imperial gallons by 1280, or use the Imperial Gallon to Imperial Fluid Drachm converter.
How many imperial gallons is 100 imperial fluid drachms?
100 imperial fluid drachms equals 0.078125 imperial gallons, because 100 × 0.00078125 = 0.078125.

Convert Imperial Fluid Drachm to other volume units

Show all Imperial Fluid Drachm conversions

Sources & references

Conversion factor (1 fl dr = 0.00078125 gal) verified against the following authoritative sources:

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