Convert Drop to US Gallon
Convert drops to us gallons instantly. 1 drop = 1.32086e-5 us gallon — use the live calculator, the exact formula, a conversion table and worked examples. Also check the US Gallon to Drop converter for the reverse conversion.
Units explained
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.
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.
Drop to US Gallon 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 drops and us gallons:
To convert drops to us gallons, multiply the value in drops by 1.32086e-5. To reverse, multiply us gallons by 75708.23568.
How to use this converter
Type a value into the calculator. The result in us 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 US Gallon to Drop converter for the reverse direction.
Step-by-step: convert drops to us gallons
- Write down the value in drops (gtt).
- Multiply that value by the factor 1.32086e-5.
- The product is the equivalent value in us gallons (gal).
- To reverse, multiply the us gallon value by 75708.23568.
Worked examples
Example 1 — Convert 1 gtt to gal:
1 × 1.32086e-5 = 1.32086e-5 gal
Example 2 — Convert 100 gtt to gal:
100 × 1.32086e-5 = 0.0013208603 gal
Real-world example — From wavelengths to millimeter-scale objects
A value of one million drops sounds vast at the atomic scale but converts to a small everyday quantity in us gallons — useful when relating optical-wavelength specifications to physical mounting hardware.
1000000 gtt × 1.32086e-5 = 13.2086026179 gal
Real-world example — Sub-micron to millimeter
500,000 drops converts to a small everyday quantity in us gallons — useful when relating optical-wavelength specifications to physical mounting hardware.
500000 gtt × 1.32086e-5 = 6.604301309 gal
Drop to US Gallon conversion table
Standard reference values for converting drops to us gallons:
| Drop [gtt] | US Gallon [gal] |
|---|---|
| 0.01 | 1.32086e-7 |
| 0.1 | 1.32086e-6 |
| 1 | 1.32086e-5 |
| 2 | 2.641721e-5 |
| 3 | 3.962581e-5 |
| 4 | 5.283441e-5 |
| 5 | 6.604301e-5 |
| 10 | 0.000132086 |
| 20 | 0.0002641721 |
| 30 | 0.0003962581 |
| 40 | 0.0005283441 |
| 50 | 0.0006604301 |
| 100 | 0.0013208603 |
| 500 | 0.0066043013 |
| 1000 | 0.0132086026 |
Frequently asked questions
How many us gallons is 1 drop?
How do I convert drops to us gallons?
How do I convert us gallons back to drops?
How many us gallons is 100 drops?
Popular volume unit conversions
Convert Drop to other volume units
Show all Drop conversions
Metric / SI (3 units)
US Customary (Liquid) (1 units)
Imperial (UK) (1 units)
Cubic (length-derived) (1 units)
Sources & references
Conversion factor (1 gtt = 1.32086e-5 gal) 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 Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.