A US fluid ounce is 1/128 of a US gallon.
Fluid ounces to Teaspoons Converter — fl oz to tsp
Convert Fluid ounce (fl oz) to Teaspoon (tsp) using the exact conversion factor (1 fluid ounce = 6 teaspoon). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Fluid ounces to Teaspoons converter
Converter
Volume Converter
Convert metric, US customary, imperial, cooking, dry, and industrial volume units.
Context values
Some unit families need one extra value for a physically accurate result.
A US teaspoon is one third of a US tablespoon.
Result = input x 2.95735296e-5 / 4.92892159e-6.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Fluid ounces to Teaspoons
Fluid ounce and Teaspoon appear side by side at fuel pumps and on beverage labels, since the US measures liquids in gallons while most of the world uses liters. Fluid ounce is typically associated with united States (beverage, nutrition labeling), while Teaspoon is typically associated with united States (cooking and recipe measurement).
Formula
teaspoons = fluid ounces × 6
This factor comes from each unit's defined relationship to the category's base unit: 1 fluid ounce equals 0.0000295735295625 base units, and 1 teaspoon equals 0.00000492892159375 base units, so dividing one by the other gives the direct fluid ounce-to-teaspoon factor of 6.
Simple example
1 fl oz × 6 = 6 tsp
1 fluid ounce = 6 teaspoons.
Real-world example
10 fl oz × 6 = 60 tsp
10 fluid ounces = 60 teaspoons.
Conversion table
| Fluid ounce (fl oz) | Teaspoon (tsp) |
|---|---|
| 1 fl oz | 6 tsp |
| 5 fl oz | 30 tsp |
| 10 fl oz | 60 tsp |
| 25 fl oz | 150 tsp |
| 50 fl oz | 300 tsp |
| 100 fl oz | 600 tsp |
Reverse conversion: Teaspoon to Fluid ounce
6 tsp × 0.1666666667 = 1 fl oz
6 teaspoons = 1 fluid ounces.
fluid ounces = teaspoons × 0.166666666667
For a page dedicated to this direction, see Teaspoon to Fluid ounce.
Fluid ounce vs. Teaspoon
| Aspect | Fluid ounce | Teaspoon |
|---|---|---|
| Family | US customary unit | US customary unit |
| Typical use | US beverage container sizing (soda, water bottles) | US recipe and cooking measurement for small quantities |
| Where it's used | United States (beverage, nutrition labeling) | United States (cooking and recipe measurement) |
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.
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
Fluid ounce — sources
- NIST Handbook 44, Appendix C — General tables of units including the US fluid ounce definition.
Teaspoon — sources
- NIST Handbook 44, Appendix C — General tables of units including the US teaspoon definition.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many teaspoons are in 1 fluid ounce?
1 fluid ounce equals 6 teaspoons, using the exact defined conversion factor rather than an estimate.
How do I convert fluid ounce to teaspoon?
Multiply the fluid ounce value by 6. The converter above does this instantly to whatever precision you set.
How do I convert teaspoon back to fluid ounce?
Use the reverse factor: 1 teaspoon equals 0.1666666667 fluid ounces. You can also use the swap control in the converter above to flip the direction instantly.
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.
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.
Is the fluid ounce to teaspoon conversion exact?
Yes. The US teaspoon is exactly 4.92892159375 milliliters — 1/3 of a US tablespoon and 1/48 of a US cup. 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 fluid ounce still used today?
United States (beverage, nutrition labeling)