Teaspoons to Milliliters Converter
Convert teaspoons to milliliters instantly and back. Supports US teaspoons (4.93 mL) and metric teaspoons (5 mL), with worked examples and a dosing and baking chart.
Updated 2026-06-14 · Free · No sign-up · Runs privately in your browser
Show the formula & steps
How the Teaspoons to Milliliters Converter Works
This converter switches between teaspoons (tsp) and milliliters (mL) in both directions, and supports both the US teaspoon (4.92892 mL) and the metric teaspoon (5 mL). Type a value, pick the system, and the result updates live with the steps shown.
The Formula
Milliliters = US teaspoons × 4.92892159 Milliliters = metric teaspoons × 5
For medicine and most charts, a teaspoon is treated as exactly 5 mL. To reverse the conversion, divide milliliters by the matching factor.
Worked Example
Convert 2 US teaspoons to milliliters:
- 2 × 4.92892159 = 9.86 mL
Convert 15 mL to metric teaspoons:
- 15 ÷ 5 = 3 metric teaspoons (also one tablespoon)
Dosing and Baking Chart
| Teaspoons | US (mL) | Metric (mL) |
|---|---|---|
| 1/2 | 2.46 | 2.5 |
| 1 | 4.93 | 5 |
| 2 | 9.86 | 10 |
| 3 (1 tbsp) | 14.79 | 15 |
| 4 | 19.72 | 20 |
A Word on Medicine
For liquid medication, always treat a teaspoon as the standardized 5 mL and measure with a marked oral syringe or dosing cup. A household teaspoon can hold anywhere from 3 to 7 mL, which can lead to under- or over-dosing. The 5 mL metric teaspoon removes that guesswork.
Frequently asked questions
How many milliliters are in a teaspoon?+
A US teaspoon is about 4.92892 mL, while a metric teaspoon is exactly 5 mL. Most medicine and recipe charts treat a teaspoon as 5 mL for simplicity.
How do I convert teaspoons to milliliters?+
For US teaspoons, multiply by 4.92892. For metric teaspoons, multiply by 5. For example, 2 metric teaspoons × 5 = 10 mL.
How many ml is 1 teaspoon of medicine?+
In medical dosing, one teaspoon is standardized as 5 mL. Always use a proper dosing spoon or oral syringe rather than kitchen cutlery, which varies in size.
How many teaspoons is 10 ml?+
10 mL equals 2 metric teaspoons, or about 2.03 US teaspoons. Divide by 5 for metric or by 4.92892 for US teaspoons.
What is the difference between US and metric teaspoons?+
The US teaspoon is 4.92892 mL and the metric teaspoon is 5 mL — a difference of about 1.4%, small enough to ignore in everyday cooking and dosing.