Convert US Gallon to US Fluid Dram
Convert us gallons to us fluid drams instantly. 1 us gallon = 1024 us fluid dram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the US Fluid Dram to US Gallon converter for the reverse conversion.
Units explained
US Gallon
The US liquid gallon is defined as exactly 231 cubic inches (3.785411784 liters).
Based on the English wine gallon of 231 cubic inches, retained by the US after 1824.
The primary US unit for fuel, milk and large beverage containers.
English wine gallon; US since 1824.
US Fluid Dram
A US fluid dram is 1/8 of a US fluid ounce (3.6967 mL).
An apothecaries' subdivision of the fluid ounce.
Historical pharmacy unit, now rare.
Apothecaries' system.
US Gallon to US Fluid Dram conversion formula
The relationship between us gallons and us fluid drams:
To convert us gallons to us fluid drams, multiply the value in us gallons by 1024. To reverse, multiply us fluid drams by 0.0009765625.
How to use this converter
Type a value into the calculator. The result in us fluid drams updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the US Fluid Dram to US Gallon converter for the reverse direction.
Step-by-step: convert us gallons to us fluid drams
- Write down the value in us gallons (gal).
- Multiply that value by the factor 1024.
- The product is the equivalent value in us fluid drams (fl dr).
- To reverse, multiply the us fluid dram value by 0.0009765625.
Worked examples
Example 1 — Convert 1 gal to fl dr:
1 × 1024 = 1024 fl dr
Example 2 — Convert 100 gal to fl dr:
100 × 1024 = 102400 fl dr
Real-world example — Adjacent small-scale precision
One us gallon equals 1,000 us fluid drams — the standard sub-millimeter precision conversion that materials engineers use whenever they switch between bulk material thickness specs (larger unit) and surface-finish characteristics (smaller unit).
1 gal × 1024 = 1024 fl dr
Real-world example — Adjacent metric sub-units
One us gallon equals 1,000 us fluid drams. Engineers move between these scales constantly: PCB feature sizes in the larger unit, wire-bond diameters in the smaller.
1 gal × 1024 = 1024 fl dr
US Gallon to US Fluid Dram conversion table
Standard reference values for converting us gallons to us fluid drams:
| US Gallon [gal] | US Fluid Dram [fl dr] |
|---|---|
| 0.01 | 10.24 |
| 0.1 | 102.4 |
| 1 | 1024 |
| 2 | 2048 |
| 3 | 3072 |
| 4 | 4096 |
| 5 | 5120 |
| 10 | 10240 |
| 20 | 20480 |
| 30 | 30720 |
| 40 | 40960 |
| 50 | 51200 |
| 100 | 102400 |
| 500 | 512000 |
| 1000 | 1024000 |
Frequently asked questions
How many us fluid drams is 1 us gallon?
How do I convert us gallons to us fluid drams?
How do I convert us fluid drams back to us gallons?
How many us fluid drams is 100 us gallons?
Popular volume unit conversions
Convert US Gallon to other volume units
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Metric / SI (15 units)
US Customary (Liquid) (14 units)
US Customary (Dry) (5 units)
Imperial (UK) (14 units)
Cubic (length-derived) (4 units)
Cooking / Culinary (5 units)
Sources & references
Conversion factor (1 gal = 1024 fl dr) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Astronomical Union — System of Astronomical Constants
The IAU defines astronomical units including the AU (149597870700 m exactly) light-year and parsec used in astronomy and astrophysics.