Volume · Unit Converter

Convert US Fluid Dram to Imperial Gallon

Convert us fluid drams to imperial gallons instantly. 1 us fluid dram = 0.0008131584 imperial gallon — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Imperial Gallon to US Fluid Dram 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

US Customary (Liquid)

US Fluid Dram

What is a us fluid dram?

A US fluid dram is 1/8 of a US fluid ounce (3.6967 mL).

Origin of the us fluid dram

An apothecaries' subdivision of the fluid ounce.

Where it is used

Historical pharmacy unit, now rare.

When and where it was developed

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.

US Fluid Dram to Imperial Gallon conversion formula

The relationship between us fluid drams and imperial gallons:

1 fl dr = 0.0008131584 gal
1 gal = 1229.772723717 fl dr

To convert us fluid drams to imperial gallons, multiply the value in us fluid drams by 0.0008131584. To reverse, multiply imperial gallons by 1229.772723717.

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 US Fluid Dram converter for the reverse direction.

Step-by-step: convert us fluid drams to imperial gallons

  1. Write down the value in us fluid drams (fl dr).
  2. Multiply that value by the factor 0.0008131584.
  3. The product is the equivalent value in imperial gallons (gal).
  4. To reverse, multiply the imperial gallon value by 1229.772723717.

Worked examples

Example 1 — Convert 1 fl dr to gal:
1 × 0.0008131584 = 0.0008131584 gal

Example 2 — Convert 100 fl dr to gal:
100 × 0.0008131584 = 0.0813158383 gal

Real-world example — Packaging gauge

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

4 fl dr × 0.0008131584 = 0.0032526335 gal

Real-world example — Plastic film and laminate thickness

A 500-us fluid dram 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 × 0.0008131584 = 0.4065791917 gal

US Fluid Dram to Imperial Gallon conversion table

Standard reference values for converting us fluid drams to imperial gallons:

US Fluid Dram [fl dr]Imperial Gallon [gal]
0.018.131584e-6
0.18.131584e-5
10.0008131584
20.0016263168
30.0024394752
40.0032526335
50.0040657919
100.0081315838
200.0162631677
300.0243947515
400.0325263353
500.0406579192
1000.0813158383
5000.4065791917
10000.8131583834

Frequently asked questions

How many imperial gallons is 1 us fluid dram?
1 us fluid dram equals 0.0008131584 imperial gallon.
How do I convert us fluid drams to imperial gallons?
Multiply the value in us fluid drams by 0.0008131584 to get imperial gallons.
How do I convert imperial gallons back to us fluid drams?
Multiply the value in imperial gallons by 1229.772723717, or use the Imperial Gallon to US Fluid Dram converter.
How many imperial gallons is 100 us fluid drams?
100 us fluid drams equals 0.0813158383 imperial gallons, because 100 × 0.0008131584 = 0.0813158383.

Convert US Fluid Dram to other volume units

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

Sources & references

Conversion factor (1 fl dr = 0.0008131584 gal) verified against the following authoritative sources:

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