Teaspoon to ML Converter
The Formula
Common Teaspoons to Milliliters Values
| Teaspoons | Milliliters | Fraction |
|---|---|---|
| 0.25 | 1.23 | 1¼ |
| 0.5 | 2.46 | 2½ |
| 0.75 | 3.70 | 3⅔ |
| 1 | 4.93 | 4⅞ |
| 1.5 | 7.39 | 7⅜ |
| 2 | 9.86 | 9⅞ |
| 3 | 14.79 | 14¾ |
| 4 | 19.72 | 19¾ |
| 5 | 24.65 | 24⅝ |
| 8 | 39.43 | 39⅜ |
| 10 | 49.29 | 49¼ |
| 12 | 59.15 | 59⅛ |
A Worked Example
A recipe calls for 1.5 teaspoons of vanilla extract. Multiply 1.5 by 4.929 to get about 7.4ml, useful when measuring with a small kitchen syringe or dropper rather than a spoon.
When This Conversion Matters
A US teaspoon equals 4.93ml, useful for converting small amounts like vanilla extract, spices, or leavening agents.
Many international recipes round this to 5ml, which is close enough for most home cooking.
Children's medicine dosing is one of the most safety-critical uses of this conversion, since kitchen teaspoons vary in actual volume far more than a calibrated medicine dosing spoon — health authorities specifically warn against substituting one for the other.
Essential oils, flavor extracts, and other highly concentrated ingredients are frequently measured by the milliliter on product labels but used by the teaspoon in home recipes, making this a common lookup in both cooking and DIY contexts.
Compounding pharmacists occasionally reference this conversion when translating an older prescription written in teaspoons into the milliliter-based dosing that modern practice standards require for patient safety.
Standards and Sources
The US teaspoon is fixed at 4.929 milliliters under NIST measurement standards — exactly 1/48 of the 236.588ml US cup, and 1/3 of the US tablespoon.
The metric teaspoon, used in pharmacology and many international recipes, is defined as exactly 5ml, a difference of under 1.5% from the US figure that most sources treat as negligible.
The U.S. Food and Drug Administration has specifically flagged household spoon inconsistency as a dosing safety issue, recommending calibrated dosing devices over kitchen teaspoons for children's liquid medicine.
The US Food and Drug Administration's guidance on over-the-counter liquid medication explicitly recommends manufacturers include a calibrated dosing device rather than relying on consumers' kitchen teaspoons for measurement.
Where This Unit Comes From
The teaspoon's dual identity — 4.929ml in the US customary system versus exactly 5ml in the metric and pharmacological systems — reflects the broader split between countries that built kitchen measurement around the cup versus those that built it around round metric numbers.
Where This Shows Up
Essential oil and flavor extract dosing in cooking or home DIY projects often specifies milliliter amounts on the product label, requiring conversion to a measurable teaspoon quantity for practical use.
Cough syrup and other over-the-counter liquid medicines list dosing in milliliters, and caregivers without a calibrated dosing device sometimes need this conversion as a rough reference, though health authorities recommend a proper dosing tool over a kitchen teaspoon.
DIY perfume and essential oil blending, a hobby where precise small-volume measurement matters for both scent balance and skin safety, commonly requires this conversion between milliliter-labeled oils and teaspoon-based recipes.
Common Mistakes
- Using a household teaspoon for medicine dosing instead of a calibrated device, which health authorities specifically warn against due to real-world spoon inconsistency.
- Treating the US (4.929ml) and metric (5ml) teaspoon as identical in a context where the small gap actually matters, like pharmaceutical dosing.
- Overfilling a teaspoon with a thick ingredient like honey, which adds unpredictable extra volume beyond the standard conversion.
- Using an old, worn measuring spoon set where repeated dishwasher cycles may have slightly warped the bowl shape and altered its true volume.
US Teaspoon vs Metric Teaspoon
| US Teaspoon | Metric Teaspoon | |
|---|---|---|
| Volume | 4.929 ml | 5 ml |
| Difference | Baseline | ~1.4% larger |
| Used in | US recipes | Pharmacology, intl. recipes |
Related Converters
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Frequently Asked Questions
How many ml are in a teaspoon?+
4.93ml, or roughly 5ml when rounded.
Is a metric teaspoon exactly 5ml?+
Yes, the metric teaspoon is defined as exactly 5ml, slightly larger than the US teaspoon.
How many ml are in a tablespoon?+
14.79ml, which is 3 teaspoons.
Should I use a kitchen teaspoon to measure children's medicine?+
No. Health authorities including the FDA recommend a calibrated oral syringe or dosing cup, since household teaspoons vary too much in actual volume for safe medicine dosing.
Why shouldn't I use a random kitchen spoon for this conversion?+
Kitchen spoons vary significantly in actual volume, sometimes by 20% or more from the standardized teaspoon, making them unreliable for precise measuring.
Does this conversion apply to thick liquids like honey?+
The volume conversion applies the same way, though thick liquids can trap air or cling to the spoon, slightly affecting the true poured amount.
Is there a standard symbol for teaspoon in recipes?+
Yes, 'tsp' or a lowercase 't' is standard in US recipes, distinct from 'tbsp' or capital 'T' for tablespoon.