How many mL has a teaspoon? Your definitive guide to liquid measurements

September 28, 2025 •

4 min read

Did you know that a standard metric teaspoon holds exactly 5 milliliters, a globally accepted standard? Understanding this key measurement is fundamental for safe and accurate dosage, especially in medicine and cooking, and answers the question of how many mL has a teaspoon.

Quick Summary

A standard metric teaspoon holds precisely 5 milliliters (mL), though its imperial and US customary counterparts can differ slightly. For accurate medication dosage and consistent cooking results, relying on a standardized measuring spoon is crucial, not the flatware from your kitchen drawer.

Key Points

Standard Metric: A metric teaspoon equals exactly 5 milliliters (mL) and is the international standard for accuracy.
US Customary: The US customary teaspoon is approximately 4.93 mL, though it is rounded to 5 mL for most practical purposes.
Never Use Flatware: The spoons in your cutlery drawer are not standardized and should never be used for precise measurements, especially for medication.
Health and Safety: Using accurate measuring spoons is critical for correctly dosing liquid medications to avoid underdosing or overdosing.
Culinary Precision: For baking and other precise recipes, using a standard measuring teaspoon ensures consistent and predictable results.
Key Conversions: A tablespoon is 15 mL (or 3 teaspoons), and half a teaspoon is 2.5 mL, helping with easy conversions.

Understanding the Standard Metric Teaspoon

In most parts of the world, especially for medical and nutritional purposes, a teaspoon is standardized to hold 5 milliliters (mL). This metric standard removes the ambiguity associated with different-sized spoons found in a cutlery set. For instance, the US Customary teaspoon is legally defined as exactly 4.92892159375 mL, but for practical applications, it's almost always rounded to a clean 5 mL for convenience.

The difference between a metric 5 mL and the US customary measurement is so miniscule that it is negligible in most home cooking scenarios. However, for applications where precision is paramount, such as preparing scientific formulas or measuring doses of medicine, the metric standard is the universal point of reference. Relying on a standardized measuring teaspoon, clearly marked with its volume, is the only way to ensure consistency and safety.

Why Your Cutlery Spoon is Not a Teaspoon

One of the most common mistakes people make is confusing a kitchen utensil with a standardized measuring tool. The average spoon you use for eating can vary in size significantly, holding anywhere from 3 mL to over 7 mL of liquid. This level of inconsistency is why using flatware for medication or sensitive recipes is not just inaccurate—it can be dangerous.

For example, when a doctor prescribes a teaspoon of cough syrup, they are referring to a medical-grade, 5 mL measuring teaspoon, not the spoon from your silverware drawer. Overdosing or underdosing, particularly with pediatric medications, can have serious health consequences. Always use the proper tools to ensure accuracy, which are often provided with the medication itself or can be purchased at a pharmacy.

Practical Applications: Health and Cooking

The importance of knowing how many mL has a teaspoon extends directly to your well-being. Precision in medication dosage is non-negotiable. Whether it’s a liquid antibiotic for a child or a daily supplement, using a standard measuring tool prevents errors that could undermine the effectiveness of a treatment or cause harm.

In the kitchen, while slight variations might not ruin a hearty stew, precision is a baker's best friend. Delicate recipes for things like soufflés or fine pastries demand accurate ratios of ingredients. A baker who relies on a precise 5 mL teaspoon will consistently achieve better and more predictable results than one who uses an unmarked spoon.

Comparison of Teaspoon Measurements

To highlight the variations, here is a helpful comparison of standard teaspoons across different systems. This illustrates why the metric 5 mL is the most reliable standard for accuracy.


System	Teaspoon Equivalent (mL)	Used For
Metric	5 mL (exactly)	Medicine, cooking (international), science
US Customary	~4.93 mL	Cooking (USA)
British Imperial	~5.92 mL	Cooking (UK, historically)

Tips for Accurate Measurement

Getting your measurements right doesn't have to be a guessing game. Follow these simple tips to ensure you are always on track:

Invest in a good set of measuring spoons: Look for a set that is clearly marked in both teaspoons and milliliters to make conversions effortless. Stainless steel or high-quality plastic sets are durable and easy to clean.
Use the correct tool for the job: For medication, prioritize oral syringes or dosing cups. These are specifically calibrated for accuracy and are far more reliable than any teaspoon.
Level your measurement: For dry ingredients measured in teaspoons, use a straight edge (like the back of a knife) to scrape away any excess, ensuring a level and accurate scoop.
Measure liquid at eye level: When measuring liquids, bend down to eye level to check the meniscus (the curve of the liquid's surface). Reading the measurement at eye level prevents parallax error, where the reading appears higher or lower depending on the viewing angle.

Advanced Conversions and Considerations

Beyond a single teaspoon, it's useful to know how other common kitchen measurements relate to milliliters. Here are some quick conversions that can come in handy:

1/2 teaspoon = 2.5 mL
1/4 teaspoon = 1.25 mL
1 tablespoon = 15 mL (which equals 3 teaspoons)
1/4 cup = 60 mL

For anyone interested in the broader context of standardized measurements and their importance in health and research, the World Health Organization's resource on metric standards is an authoritative source. This is particularly relevant for those dealing with international recipes or pharmaceutical guidelines.

Conclusion: Making Informed Choices

The simple question, "How many mL has a teaspoon?" opens a door to a wider understanding of measurement accuracy in our daily lives. From preventing a medical mishap to ensuring your holiday baking turns out perfectly, using a standardized 5 mL teaspoon is the best practice. By moving away from the guesswork of using silverware, you embrace precision and safety, benefiting your health and elevating your culinary creations. Investing in proper measuring tools is a small step that yields significant rewards.

Frequently Asked Questions

For most international and medical applications, yes, a standard measuring teaspoon is defined as exactly 5 mL. However, older or regional measurements can vary slightly, so it is always best to use a metric measuring spoon.

Kitchen spoons are not standardized and their volumes vary widely. Using one for medication can lead to dangerous dosing errors. Always use a proper oral syringe, dosing cup, or a standard metric measuring spoon for safety.

Since one metric teaspoon is 5 mL, half a teaspoon is simply 2.5 mL. Most sets of measuring spoons include a 1/2 tsp, and many oral syringes have marks for 2.5 mL.

A tablespoon (Tbsp) is a larger unit of measurement. It is equivalent to 3 teaspoons (tsp), so one standard metric tablespoon holds 15 mL.

For many general cooking recipes, a small deviation may be acceptable. However, for baking and delicate recipes where chemical reactions are key, precise measurements are crucial for the desired outcome. For medication, precision is always non-negotiable.

For liquid medication, oral syringes are often the most accurate and easiest to use, especially for small doses. They are clearly marked and prevent spills, which is why they are often recommended by healthcare professionals.

Most modern recipes and especially those involving metric units will assume a standard 5 mL teaspoon. If the source is historical or explicitly from a non-metric country, use a metric 5 mL spoon unless specified otherwise, as it is the most widely accepted standard.