A US teaspoon is one third of a US tablespoon.
Teaspoons to Fluid ounces Converter — tsp to fl oz
Convert Teaspoon (tsp) to Fluid ounce (fl oz) using the exact conversion factor (1 teaspoon = 0.1666666667 fluid ounce). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Teaspoons to Fluid ounces converter
Converter
Cooking Converter
Convert cooking volume and mass units used in recipes and nutrition workflows.
Context values
Some unit families need one extra value for a physically accurate result.
A US fluid ounce is 1/128 of a US gallon.
Result = input x 4.92892159e-6 / 2.95735296e-5.
Volume units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Teaspoons to Fluid ounces
Teaspoon and Fluid ounce both show up in recipes, and converting between them matters whenever a recipe from one country's cookbook needs to be followed with another country's measuring tools. Teaspoon is typically associated with united States (cooking and recipe measurement), while Fluid ounce is typically associated with united States (beverage, nutrition labeling).
Formula
fluid ounces = teaspoons × 0.166666666667
This factor comes from each unit's defined relationship to the category's base unit: 1 teaspoon equals 0.00000492892159375 base units, and 1 fluid ounce equals 0.0000295735295625 base units, so dividing one by the other gives the direct teaspoon-to-fluid ounce factor of 0.166666666667.
Simple example
1 tsp × 0.1666666667 = 0.1666666667 fl oz
1 teaspoon = 0.1666666667 fluid ounces.
Real-world example
2 tsp × 0.1666666667 = 0.3333333333 fl oz
2 teaspoons = 0.3333333333 fluid ounces.
Conversion table
| Teaspoon (tsp) | Fluid ounce (fl oz) |
|---|---|
| 0.25 tsp | 0.0416666667 fl oz |
| 0.5 tsp | 0.0833333333 fl oz |
| 1 tsp | 0.1666666667 fl oz |
| 2 tsp | 0.3333333333 fl oz |
| 4 tsp | 0.6666666667 fl oz |
| 8 tsp | 1.333333333 fl oz |
Reverse conversion: Fluid ounce to Teaspoon
0.1666666667 fl oz × 6 = 1 tsp
0.1666666667 fluid ounces = 1 teaspoons.
teaspoons = fluid ounces × 6
For a page dedicated to this direction, see Fluid ounce to Teaspoon.
Teaspoon vs. Fluid ounce
| Aspect | Teaspoon | Fluid ounce |
|---|---|---|
| Family | US customary unit | US customary unit |
| Typical use | US recipe and cooking measurement for small quantities | US beverage container sizing (soda, water bottles) |
| Where it's used | United States (cooking and recipe measurement) | United States (beverage, nutrition labeling) |
Understanding the Teaspoon
Teaspoon (tsp) measures volume. The US teaspoon is exactly 4.92892159375 milliliters — 1/3 of a US tablespoon and 1/48 of a US cup. It is classified as a US customary unit.
Where it's used: United States (cooking and recipe measurement)
Uses of the Teaspoon today
- US recipe and cooking measurement for small quantities
- Medication dosing instructions in the US
- Baking measurement alongside the tablespoon and cup
Understanding the Fluid ounce
Fluid ounce (fl oz) measures volume. The US fluid ounce is 1/128 of a US gallon: exactly 29.5735295625 milliliters. It is classified as a US customary unit.
Where it's used: United States (beverage, nutrition labeling)
Uses of the Fluid ounce today
- US beverage container sizing (soda, water bottles)
- US nutrition and medication dosing labels
History of the Fluid ounce
The US fluid ounce follows from the same English wine-gallon system as the rest of the US liquid volume units, defined as a consistent fraction of the gallon.
Historical origin. Fluid ounce was not the invention of a single named person; it developed through the process described above.
Teaspoon — sources
- NIST Handbook 44, Appendix C — General tables of units including the US teaspoon definition.
Fluid ounce — sources
- NIST Handbook 44, Appendix C — General tables of units including the US fluid ounce definition.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many fluid ounces are in 1 teaspoon?
1 teaspoon equals 0.1666666667 fluid ounces, using the exact defined conversion factor rather than an estimate.
How do I convert teaspoon to fluid ounce?
Multiply the teaspoon value by 0.1666666667. The converter above does this instantly to whatever precision you set.
How do I convert fluid ounce back to teaspoon?
Use the reverse factor: 1 fluid ounce equals 6 teaspoons. You can also use the swap control in the converter above to flip the direction instantly.
What is a teaspoon?
Teaspoon (tsp) measures volume. The US teaspoon is exactly 4.92892159375 milliliters — 1/3 of a US tablespoon and 1/48 of a US cup. It is classified as a US customary unit.
What is a fluid ounce?
Fluid ounce (fl oz) measures volume. The US fluid ounce is 1/128 of a US gallon: exactly 29.5735295625 milliliters. It is classified as a US customary unit.
Is the teaspoon to fluid ounce conversion exact?
Yes. The US fluid ounce is 1/128 of a US gallon: exactly 29.5735295625 milliliters. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the teaspoon still used today?
United States (cooking and recipe measurement)