Milliliters to teaspoons (ml to tsp) converter

What is the ml to tsp conversion?

Turning milliliters (ml) into teaspoons (tsp) is something you do all the time in the kitchen, in the medicine cabinet, and in the lab. A teaspoon is a small unit of volume, and depending on where you are it holds a slightly different amount of liquid. Knowing the exact relationship lets you scale a recipe up or down, measure a dose of cough syrup, or follow instructions written for a different region without guessing.

Types of teaspoons

The capacity of a teaspoon is not the same everywhere. A small difference per spoon adds up when a recipe calls for many of them, so it pays to know which definition you are using. The three you will meet most often are:

1. US Customary teaspoon: Approximately 4.92892 ml.
2. Metric teaspoon: Exactly 5 ml, the value used in most of the world and in nutrition labelling.
3. UK (imperial) teaspoon: Approximately 5.91939 ml, the largest of the three.

Choosing the right definition matters most when accuracy counts, such as dosing medicine or baking, where a small error can change the result.

Table of common teaspoon conversions

The table below shows how a handful of common milliliter amounts translate into each kind of teaspoon, so you can check a value at a glance instead of reaching for a calculator.

A quick lookup like this helps avoid slips in manual arithmetic.

Formula

The formula used to convert ml to tsp depends on which regional teaspoon you have in mind. Here are the three you need:

• US teaspoon:

  $$\text{tsp} = \frac{\text{ml}}{4.92892}$$

• Metric teaspoon:

  $$\text{tsp} = \frac{\text{ml}}{5}$$

• UK teaspoon:

  $$\text{tsp} = \frac{\text{ml}}{5.91939}$$

To go the other way, multiply the number of teaspoons by the same factor instead of dividing.

Examples

A couple of worked examples make the formulas concrete.

Example 1: Converting 10 ml to tsp

• US teaspoon: $\text{tsp} = \frac{10 \, \text{ml}}{4.92892} \approx 2.03 \, \text{tsp}$

• Metric teaspoon: $\text{tsp} = \frac{10 \, \text{ml}}{5} = 2 \, \text{tsp}$

• UK teaspoon: $\text{tsp} = \frac{10 \, \text{ml}}{5.91939} \approx 1.69 \, \text{tsp}$

Example 2: Converting 5 ml to tsp

• US teaspoon: $\text{tsp} = \frac{5 \, \text{ml}}{4.92892} \approx 1.01 \, \text{tsp}$

• Metric teaspoon: $\text{tsp} = \frac{5 \, \text{ml}}{5} = 1 \, \text{tsp}$

• UK teaspoon: $\text{tsp} = \frac{5 \, \text{ml}}{5.91939} \approx 0.84 \, \text{tsp}$

These show how the chosen standard nudges the answer, which is why it helps to pick one before you start.

Frequently asked questions

How many tsp are in 15 ml of liquid?

For the US teaspoon: $\text{tsp} = \frac{15 \, \text{ml}}{4.92892} \approx 3.04 \, \text{tsp}$

For the metric teaspoon: $\text{tsp} = \frac{15 \, \text{ml}}{5} = 3 \, \text{tsp}$

For the UK teaspoon: $\text{tsp} = \frac{15 \, \text{ml}}{5.91939} \approx 2.53 \, \text{tsp}$

Is 5 ml always exactly one teaspoon?

Only for the metric teaspoon, which is defined as 5 ml. A US teaspoon is a little smaller at about 4.93 ml, so 5 ml is just over one US teaspoon, while a UK teaspoon is larger at about 5.92 ml, so 5 ml is a bit less than one. Medicine doses are usually given in metric teaspoons of 5 ml.

Which teaspoon should I use for a recipe that does not say?

Look at where the recipe comes from. Most modern recipes assume the metric teaspoon of 5 ml, and American recipes use the US teaspoon, which is so close to 5 ml that the difference rarely matters in cooking.

How many ml are in a teaspoon of medicine?

A medicinal teaspoon is standardised at 5 ml, matching the metric teaspoon, so a dose of “one teaspoon” means 5 ml. For an exact dose it is best to use a marked measuring spoon or syringe rather than a kitchen spoon.