What this conversion means in practice
This page is intentionally focused on one volume pair so you can convert quickly without scanning a long all-purpose tool. These conversions are used in cooking, nutrition, labeling, fluid handling, lab work, and logistics where unit systems often get mixed.
The governing relationship here is 1 teaspoon = 4.92892159375 ml. If results look suspicious, check whether the source value is US or metric, and confirm that abbreviations match the expected unit family. In volume, that matters because similar labels can represent different systems.
Use the calculator for exact values, the conversion table for quick references, and the unit notes below when you need context for reports, recipes, product specs, or technical instructions.
How to convert teaspoon (us) to milliliter
Multiply the teaspoon (us) value by 4.92892159375 to get milliliter.
Example: 15 teaspoon × 4.92892159375 = 73.93382390625 ml
Teaspoon (US)
Definition: A US teaspoon is exactly 1/6 US fluid ounce, or about 4.9289 mL.
History and origin: Historically varied in household use, but now fixed in US customary definitions.
Current use: Used for recipes and small measured doses in household contexts.
Milliliter
Definition: A milliliter (mL) is one-thousandth of a liter, equal to one cubic centimeter.
History and origin: It became standard as metric measurement spread through medicine, chemistry, and food labeling.
Current use: Used for medication doses, recipes, nutrition labels, and lab measurement.
Teaspoon (US) to Milliliter conversion table
| Teaspoon (US) (teaspoon) | Milliliter (ml) |
|---|---|
| 0.1 teaspoon | 0.4928921594 ml |
| 1 teaspoon | 4.9289215938 ml |
| 2 teaspoon | 9.8578431875 ml |
| 3 teaspoon | 14.7867647813 ml |
| 5 teaspoon | 24.6446079688 ml |
| 10 teaspoon | 49.2892159375 ml |
| 20 teaspoon | 98.578431875 ml |
| 50 teaspoon | 246.4460796875 ml |
| 100 teaspoon | 492.892159375 ml |
| 1,000 teaspoon | 4,928.92159375 ml |
Teaspoon (US) to Milliliter FAQ
Is this factor exact?
Some conversion links are exact by unit definition, while display values may be rounded for readability. Use higher precision when documenting formulas, labels, or technical specs.
Why do volume mistakes happen so often?
Volume has many similarly named units across systems. US and UK gallons differ, fluid ounces differ by system, and kitchen shorthand can hide assumptions. Verify system and abbreviation first.
How many decimals should I keep?
Recipes often use low precision, while production and lab workflows may require more. Keep a precision standard across your workflow to avoid compounding rounding differences.