Convert Imperial Gallon to Drop
Convert imperial gallons to drops instantly. 1 imperial gallon = 90921.8 drop — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Drop to Imperial Gallon converter for the reverse conversion.
Units explained
Imperial Gallon
The imperial gallon is defined as exactly 4.54609 liters.
Set by the British Weights and Measures Act of 1824 as the volume of 10 lb of water.
Used for fuel and beverages in the UK and Commonwealth.
UK, 1824.
Drop
A drop is a nominal small volume of about 0.05 mL; the exact size varies with the liquid and dropper.
Standardized loosely in pharmacy as roughly 1/20 of a milliliter (the metric drop).
Used for liquid medication and flavor dosing; treat as approximate.
Pharmacy convention.
Imperial Gallon to Drop conversion formula
Note: this conversion uses a generally accepted modern value. Historical and regional definitions of this unit varied across times and places.
The relationship between imperial gallons and drops:
To convert imperial gallons to drops, multiply the value in imperial gallons by 90921.8. To reverse, multiply drops by 1.099846e-5.
How to use this converter
Type a value into the calculator. The result in drops updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Drop to Imperial Gallon converter for the reverse direction.
Step-by-step: convert imperial gallons to drops
- Write down the value in imperial gallons (gal).
- Multiply that value by the factor 90921.8.
- The product is the equivalent value in drops (gtt).
- To reverse, multiply the drop value by 1.099846e-5.
Worked examples
Example 1 — Convert 1 gal to gtt:
1 × 90921.8 = 90921.8 gtt
Example 2 — Convert 100 gal to gtt:
100 × 90921.8 = 9092180 gtt
Real-world example — Small-scale to atomic-scale
One imperial gallon equals 10 million drops — useful for physics curricula that relate everyday measurements to atomic and optical scales.
1 gal × 90921.8 = 90921.8 gtt
Real-world example — Centimeter to wavelength scale
One imperial gallon equals 10 million drops. Physics curricula use this kind of conversion to relate everyday measurements to atomic and optical scales.
1 gal × 90921.8 = 90921.8 gtt
Imperial Gallon to Drop conversion table
Standard reference values for converting imperial gallons to drops:
| Imperial Gallon [gal] | Drop [gtt] |
|---|---|
| 0.01 | 909.218 |
| 0.1 | 9092.18 |
| 1 | 90921.8 |
| 2 | 181843.6 |
| 3 | 272765.4 |
| 4 | 363687.2 |
| 5 | 454609 |
| 10 | 909218 |
| 20 | 1818436 |
| 30 | 2727654 |
| 40 | 3636872 |
| 50 | 4546090 |
| 100 | 9092180 |
| 500 | 4.54609e+7 |
| 1000 | 9.09218e+7 |
Frequently asked questions
How many drops is 1 imperial gallon?
How do I convert imperial gallons to drops?
How do I convert drops back to imperial gallons?
How many drops is 100 imperial gallons?
Popular volume unit conversions
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Metric / SI (15 units)
US Customary (Liquid) (15 units)
US Customary (Dry) (5 units)
Imperial (UK) (13 units)
Cubic (length-derived) (4 units)
Cooking / Culinary (5 units)
Sources & references
Conversion factor (1 gal = 90921.8 gtt) 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.