Teaspoons to Milliliters Converter

One US teaspoon equals 4.929 milliliters. Multiply teaspoons by 4.929 to convert. In practice, 1 teaspoon is rounded to 5 mL for cooking and medicine. For example, 2 teaspoons = about 10 mL.

Teaspoons

tsp

Milliliters

Common Conversions

Key Takeaways

1 US teaspoon = 4.929 mL. 1 metric teaspoon = exactly 5 mL.
3 teaspoons = 1 tablespoon = ~15 mL.
Medicine dosing uses the 5 mL metric standard — use a syringe, not a kitchen spoon.
Common baking amounts: ½ tsp = 2.5 mL, 1 tsp = 5 mL, 2 tsp = 10 mL.
The US/metric difference (0.07 mL) is negligible for cooking but matters in pharmacy.

How Do You Convert Teaspoons to Milliliters?

Multiply the number of teaspoons by 4.929 to get milliliters (US customary). The formula is: mL = teaspoons × 4.929. For practical cooking, round up to 5 mL per teaspoon, which is the metric standard used on measuring spoons and medicine cups worldwide.

Leah Novak measures vanilla extract for her bakery's signature cupcakes. Her recipe calls for 1½ teaspoons of vanilla per batch. Converting: 1.5 × 5 = 7.5 mL. When she scales up to 10 batches for a weekend rush, she needs 75 mL — easier to measure with a graduated cylinder than counting 15 teaspoons.

Teaspoons to mL Reference Table

Teaspoons	Milliliters (metric)	Common Use
¼ tsp	1.25 mL	Spice pinch
½ tsp	2.5 mL	Baking powder per cup flour
1 tsp	5 mL	Standard medicine dose
1½ tsp	7.5 mL	Vanilla extract per batch
2 tsp	10 mL	Cough syrup adult dose
3 tsp	15 mL	1 tablespoon
4 tsp	20 mL	Salad dressing per serving
6 tsp	30 mL	2 tablespoons / 1 fl oz
12 tsp	60 mL	¼ cup
48 tsp	240 mL	1 cup

Cooking and Medicine Uses

Baking Precision

In baking, small measurement errors compound. If a cookie recipe calls for 1 teaspoon of baking soda and you accidentally use 2 teaspoons (10 mL instead of 5 mL), the cookies will spread too much and taste bitter. Leah keeps a set of metric measuring spoons (1.25, 2.5, 5, and 15 mL) alongside her US set to handle recipes from any source.

Medicine Dosing

Pediatric medications are prescribed in mL, not teaspoons, precisely because kitchen spoons are unreliable. A children's fever reducer might prescribe 7.5 mL for a child weighing 40 pounds. If a parent uses a large kitchen teaspoon delivering 7 mL instead, the child gets a subtherapeutic dose. The American Academy of Pediatrics recommends milliliter-only dosing for all liquid medications.

International Recipe Conversion

Marco Ferreira adapts Italian recipes for his Pinewood Falls restaurant. Italian recipes often list small liquid amounts in mL. When a recipe calls for 10 mL of olive oil, he knows that is 2 teaspoons — easy to measure with his US spoon set. For larger amounts, he switches to his graduated measuring cup.

Frequently Asked Questions

How many milliliters are in a teaspoon?

One US teaspoon equals 4.92892 mL. A metric teaspoon is exactly 5 mL. Most recipes and medicine dosing guides use the 5 mL standard. For precise baking or pharmaceutical measurements, know which teaspoon standard is being referenced.

Is a teaspoon 5 mL or 4.93 mL?

A metric teaspoon is exactly 5 mL, while a US customary teaspoon is 4.92892 mL. In cooking, the difference (0.07 mL) is negligible. Medicine cups and syringes use the 5 mL metric standard, which is why doctors say "one teaspoon equals 5 mL."

How do I measure medicine in teaspoons?

Use a proper medicine syringe or dosing cup marked in mL, not a kitchen teaspoon. Kitchen teaspoons vary in size and can deliver 3-7 mL instead of the intended 5 mL dose. The FDA recommends using mL-marked devices for accurate dosing.

How many teaspoons are in a tablespoon?

There are 3 teaspoons in 1 tablespoon. In metric terms, 1 tablespoon = 15 mL and 1 teaspoon = 5 mL (metric). In US customary, 1 tablespoon = 14.79 mL and 1 teaspoon = 4.93 mL.

What is the difference between US and UK teaspoons?

A US teaspoon is 4.93 mL. A UK (imperial) teaspoon was historically 5.92 mL, but modern UK recipes now use the metric 5 mL teaspoon. Australian teaspoons are also 5 mL. Always check which standard a recipe uses.