What Is Drop?
A drop is a tiny amount of liquid that falls from something like a bottle, pipette, or dropper. In measuring, a drop is used to give small doses, often for medicine, chemicals, and essential oils.
Definition
A drop is a small unit for measuring volume. It is not exactly the same everywhere, but in many medical and science uses, people treat:
- 1 drop as about 0.05 milliliter (mL), which is about 20 drops in 1 mL
Some tools make smaller drops on purpose. These are called microdrops. A microdrop is often taken as:
- 1 microdrop as about 0.01 milliliter (mL), which is about 60 microdrops in 1 mL
Because real drops can change with bottle shape, liquid thickness, and temperature, the drop is an approximate unit. That means it is close, but not perfectly exact, unless a special dropper is used.
History / Origin
People have noticed and used drops of liquid since ancient times. Long ago, doctors and pharmacists gave medicine by counting drops, because they did not always have good spoons or accurate scales.
The word for drop in Latin is gutta. Early European doctors wrote prescriptions in Latin and used the word guttae, meaning drops. From this, the common symbol gtt for drops was created.
Before modern metric units, several traditional systems used drops to measure liquid medicine. As science and industry grew, people realized that natural drops are not all the same size. This led to the use of special droppers and more exact rules, like deciding that a standard drop in medicine equals a certain fraction of a milliliter.
Symbol & Abbreviation
Several symbols are used for the unit drop:
- gtt – most common medical abbreviation, from Latin “guttae” (drops)
- gt – sometimes used as a short form of gtt
- gtt(s) – used when writing prescriptions, meaning one or more drops
- drop or drops – written in full in plain language instructions
For very small drops made by special tubing, you may see:
- microdrop or µgtt – a very small, more exact drop size, often used in some IV sets
Current Use Around the World
Today, the drop is still used in many areas, but usually only for small amounts of liquid where spoons are not practical.
Common uses include:
- Medicine: eye drops, ear drops, nose drops, liquid vitamins, and other drugs that must be given in very small doses
- IV drips: hospitals count drops per minute to control how fast liquid medicine goes into a patient through a tube
- Laboratories: chemists and technicians add liquids drop by drop for tests and reactions
- Essential oils and fragrances: used in aromatherapy or perfumes, where only a few drops are needed
- Cooking and food flavoring: sometimes recipes say “a few drops” of coloring, flavoring, or strong sauces
Even though the drop is widely used, most countries use the metric system for exact volume measurements. So in serious medical and scientific work, the drop is usually linked to milliliters, such as saying that a particular dropper gives 20 drops per 1 milliliter.
Example Conversions
These sample conversions use the common medical rule:
- 1 mL = 20 drops
- 1 drop = 0.05 mL
Drops to milliliters (mL)
- 5 drops ≈ 0.25 mL
- 10 drops ≈ 0.5 mL
- 20 drops ≈ 1 mL
- 40 drops ≈ 2 mL
- 100 drops ≈ 5 mL
Milliliters (mL) to drops
- 0.5 mL ≈ 10 drops
- 1 mL ≈ 20 drops
- 2.5 mL ≈ 50 drops
- 5 mL ≈ 100 drops
Drops to common kitchen units (using 5 mL = 1 teaspoon):
- 1 teaspoon (5 mL) ≈ 100 drops
- 1 tablespoon (15 mL) ≈ 300 drops
- 1 cup (240 mL, cooking measure) ≈ 4,800 drops
Remember, these are only approximate values. Real drops may be a bit bigger or smaller depending on the dropper and the liquid.
Related Units
Units commonly related to the drop include:
- Milliliter (mL): main metric unit for small liquid volumes. About 20 drops make 1 mL in many medical systems.
- Liter (L): larger metric unit for liquid volume. 1,000 mL equals 1 liter.
- Teaspoon (tsp): kitchen unit. Often taken as 5 mL, which is about 100 drops by the medical rule.
- Tablespoon (Tbsp): kitchen unit. Often taken as 15 mL, about 300 drops.
- Minim: an old apothecary unit. It was once defined using a very small drop size, but is rarely used now.
- Fluid dram: another old medicine unit, larger than a minim, used in apothecary systems.
- Microdrop: a specially defined small drop, often used in IV tubes and some precise droppers.
FAQs
Is a drop an exact measurement?
No. A drop is not perfectly exact. The size of a drop can change with the dropper, the liquid, and other conditions. In medical and lab work, workers try to control these things or use droppers made to give a fixed number of drops per milliliter.
How many drops are in 1 milliliter?
In many medical settings, 1 milliliter is treated as 20 drops. Some special IV sets and droppers may use 60 drops per milliliter for microdrops. Always check the label or instructions, because the number can be different.
How big is 1 drop in milliliters?
Using the common 20 drops per milliliter rule, 1 drop is about 0.05 mL. With some microdrop sets, 1 drop might be about 0.016 to 0.02 mL. Real drops can vary, so this is only approximate.
Are all drops the same size?
No. Drops from a thick liquid like syrup are usually larger and fall more slowly. Drops from a thin liquid like water or alcohol are often smaller. Also, different droppers and bottle tips can make different drop sizes.
What is the difference between a drop and a microdrop?
A normal drop is the usual small amount of liquid that falls from a standard dropper. A microdrop is a specially designed smaller drop, made so that many more drops equal 1 mL, often 60 drops per mL instead of 20.
Why do doctors and nurses still use drops?
Drops are helpful for giving very small amounts of liquid, especially for eyes, ears, nose, and some strong medicines. It would be hard to measure such tiny amounts with a spoon. However, for safety, medical staff usually link drops to mL using known droppers and written rules.
Is it safe to guess the number of drops from a random bottle?
It is not safe to guess for important medicines. If the dose is very important, follow the instructions on the bottle, ask a doctor or pharmacist, and use the dropper that came with the medicine. Different bottles can give very different drop sizes.
How can I measure drops more accurately at home?
Use the dropper or measuring tool that came with the medicine or product. Keep the dropper straight, squeeze gently and evenly, and follow the written instructions. If the label lists mL as well as drops, use a small marked syringe or cup to measure by mL for better accuracy.
Can I replace drops with teaspoons in a recipe?
For strong things like food coloring, flavor extracts, or very spicy sauces, it is better to use drops as written, because even a small change can affect taste. If you must change, remember that about 100 drops equal 1 teaspoon by the common medical rule, but actual cooking drops may be different, so adjust carefully.