Whether 3 teaspoons is equal to 15 mL is a common question that arises in cooking and baking, when measuring out ingredients that require specific amounts of liquids. Having an understanding of converting between teaspoons and milliliters is important for accurately following recipes and getting the right results.

## The Quick Answer

Yes, 3 teaspoons is approximately equal to 15 mL. However, the exact conversion depends slightly on the type of teaspoon used.

### Teaspoon and Milliliter Conversions

There are a few different types of teaspoons that are commonly used:

- Metric teaspoon: Exactly 5 mL
- US customary teaspoon: Approximately 4.93 mL
- Imperial teaspoon (UK): Approximately 4.74 mL

So for the different teaspoon types:

- 3 metric teaspoons = 15 mL exactly
- 3 US teaspoons = 14.79 mL
- 3 Imperial (UK) teaspoons = 14.22 mL

As you can see, the metric teaspoon of 5 mL converts exactly to 15 mL for 3 teaspoons. The other types result in a number close to 15 mL when you multiply by 3 teaspoons, but not exactly 15 mL.

## Metric Conversions

Let’s take a closer look at the metric conversions:

- 1 metric teaspoon = 5 mL exactly
- 1 tablespoon = 15 mL exactly
- 1 fluid ounce = 30 mL exactly
- 1 cup = 240 mL exactly

The metric system has been designed to make converting between units straightforward. All of the conversions are based on multiples of 10.

So 3 metric teaspoons equals:

- 3 teaspoons x 5 mL per teaspoon = 15 mL

This shows that in the metric system, 3 teaspoons is equivalent to 15 mL.

### US Customary Conversions

For US customary units, the conversions are not as neat in multiples of 10, but are approximately:

- 1 US teaspoon = 4.93 mL
- 1 US tablespoon = 14.79 mL
- 1 US fluid ounce = 29.57 mL
- 1 US cup = 236.59 mL

So for 3 US teaspoons:

- 3 teaspoons x 4.93 mL per teaspoon = 14.79 mL

This equals 14.79 mL, which is close to 15 mL but not an exact match.

### Imperial (UK) Conversions

The Imperial system used in the UK has slightly different conversions:

- 1 Imperial teaspoon = 4.74 mL
- 1 Imperial tablespoon = 14.21 mL
- 1 Imperial fluid ounce = 28.41 mL
- 1 Imperial cup = 284.13 mL

So for 3 Imperial teaspoons:

- 3 teaspoons x 4.74 mL per teaspoon = 14.22 mL

Again this is close to 15 mL but not an exact conversion.

## Summary of 3 Teaspoons to mL

To summarize:

Teaspoon Type | 3 Teaspoons in mL |
---|---|

Metric Teaspoon | 15 mL |

US Teaspoon | 14.79 mL |

Imperial (UK) Teaspoon | 14.22 mL |

So while 3 metric teaspoons = 15 mL exactly, for other teaspoon types the conversion is close but not exact. The differences are small though.

## When Accuracy Matters

For most everyday cooking and baking, the small differences between 3 non-metric teaspoons and 15 mL won’t make a noticeable difference. As long as you’re consistent in the units you use, substituting 3 teaspoons for 15 mL or vice versa will give good results.

However, there are some situations where accuracy is extra important. Examples include:

- Following medical dosing instructions
- Measuring chemicals for scientific experiments
- Making commercial products that rely on precise measurements

In these cases, you should avoid mixing units between metric and non-metric systems. Use a proper measuring tool designed for the units needed, rather than approximating conversions.

## Tips for Measuring Teaspoons and Milliliters

Here are some tips when working with teaspoons and milliliters in cooking and baking:

**Use measuring spoons or cups designed for the units needed**– Don’t substitute regular cutlery teaspoons in place of measuring spoons for accuracy.**Level off ingredients**– Use a straight edge like the back of a knife to level off dry ingredients measured in teaspoons or tablespoons for accuracy.**Use graduated measuring cups or syringes for small mL amounts**– The thin lines on these make reading milliliter amounts easy.**Work in either metric or US customary units**– Avoid mixing the two systems where possible.**Use metric for science experiments or medical dosing**– For precision, metric units like mL are best.

## Frequently Asked Questions

### Why are there different types of teaspoons?

Different types of teaspoons exist because historically there were various systems of measurement used in different countries. The metric system was introduced to try to standardize units across the globe based on universal standards. Today, the metric system (and metric teaspoons) are widely used for science, medicine and cooking.

### Can I use any small spoon as a teaspoon when cooking?

It’s better to use an actual measuring teaspoon rather than a random small spoon. Measuring spoons are designed to all be the same size according to the units they measure. Using an odd small spoon could throw your measurements off.

### Should I buy a set of measuring spoons?

Having a set of measuring spoons that includes 1/4 teaspoon, 1/2 teaspoon, 1 teaspoon, and 1 tablespoon is handy for baking and cooking. You can find inexpensive but good quality stainless steel measuring spoon sets at most grocery and home stores. They will last a long time.

### What’s the difference between a milliliter and a liter?

A milliliter (mL) is 1/1000 of a liter. A liter itself is a larger unit equal to 1000 mL. For context, 1 teaspoon is around 5 mL, while an entire bottle of soda may be 500 mL or 0.5 liters.

## Conclusion

While 3 metric teaspoons equals 15 mL exactly, for other teaspoon types the conversion to milliliters results in a number very close to but not precisely 15 mL. The differences are small though, and in everyday cooking substituting 3 non-metric teaspoons for 15 mL will usually result in negligible differences.

However, for scientific, medical or commercial uses requiring precision, you should only use metric units or avoid mixing metric and non-metric systems. Using proper measuring tools for the units needed will improve accuracy.

Knowing teaspoon to milliliter conversions can help you successfully work with recipes and measuring ingredients for cooking, baking and other applications.