Milliliters to Teaspoons Converter
Convert milliliters to US teaspoons — for a metric label measured with American spoons.
Updated
US teaspoons
1.01tsp
5 mL = 1.01 tsp
In short
How many teaspoons is 5 mL?
5 millilitres is 1.01 US teaspoons, so for any practical purpose it is one teaspoon. The US teaspoon is 4.93 millilitres and the metric one is a round 5, a difference of 1.44 percent that no spoon can express. For medicine, use the marked syringe or cup supplied with the bottle rather than any spoon.
On a medicine label a teaspoon means 5 mL by pharmaceutical convention, which is why doses are written as one teaspoon, 5 mL.
milliliters to US teaspoons — quick reference
| milliliters (mL) | US teaspoons (tsp) |
|---|---|
| 1 mL | 0.20 tsp |
| 2.5 mL | 0.51 tsp |
| 5 mL | 1.01 tsp |
| 7.5 mL | 1.52 tsp |
| 10 mL | 2.03 tsp |
| 15 mL | 3.04 tsp |
| 20 mL | 4.06 tsp |
| 30 mL | 6.09 tsp |
The formula, worked line by line
The conversion divides by a constant that was defined rather than measured. The US teaspoon is one sixth of the US fluid ounce, the fluid ounce is a hundred and twenty-eighth of the US liquid gallon, and the gallon is exactly 231 cubic inches. Fixing the inch at 2.54 centimetres in 1959 made every figure downstream exact.
“The US gallon is exactly 231 cubic inches, and the inch is exactly 2.54 centimetres.”
Because each step is exact, the arithmetic contributes nothing to the error. Whatever ends up in the pan or the dosing cup is decided by the spoon, the fill and the pour, which is why this page spends more words on instruments than on decimals.
tsp = mL / 4.92892159375
4.92892159375 = 29.5735295625 / 6 (the fluid ounce, split six ways)
5 mL -> 5 / 4.92892159375 = 1.01 tsp
15 mL -> 15 / 4.92892159375 = 3.04 tsp
3 tsp = 1 tbsp - 6 tsp = 1 fl oz - 48 tsp = 1 cup- Millilitres entered
- 5
- Exact divisor
- 4.92892159375 mL per teaspoon
- Division
- 5 / 4.92892159375 = 1.0144
- US teaspoons
- 1.01 tsp
The 0.01 is the entire difference between the metric and customary teaspoon, and it is smaller than the film of liquid left clinging to a spoon after pouring. It is the reason the two units have coexisted for a century without anyone needing to choose.
Where the tablespoon stops being three teaspoons
Three teaspoons make a tablespoon almost everywhere. Australia is the exception, with a 20 millilitre tablespoon that works out to four metric teaspoons. Converting 20 millilitres here returns 4.06 US teaspoons, which is the tell: if a recipe treats a tablespoon as four teaspoons, it is Australian.
- US customary tablespoon
- 14.79 mL, 3 US teaspoons
- Metric tablespoon, UK and most of Europe
- 15 mL, 3 metric teaspoons
- FDA nutrition-labelling tablespoon
- 15 mL
- Australian tablespoon
- 20 mL, 4 metric teaspoons
The Australian spoon is 35.26 percent larger than the US one. Three of them in a recipe is the difference between one fluid ounce and one and a half.
When to stop using spoons altogether
Above about 50 millilitres a spoon becomes the wrong instrument. Ten teaspoonfuls poured one at a time accumulate spillage and lose count far more reliably than a jug misreads. A quarter cup is 60 millilitres, and at that point a measuring cup is both faster and more accurate.
How to use the milliliters to teaspoons converter
One US teaspoon is 4.92892159375 millilitres, so dividing by it turns any metric quantity into American spoons. The number is awkward because the teaspoon was never defined against the millilitre: it is a sixth of a US fluid ounce, which is a gallon of 231 cubic inches split 128 ways.
In practice the figure you need is that 5 millilitres is 1.01 teaspoons. A metric spoon and a US teaspoon are the same thing in any kitchen, differing by about one and a half drops. That is far below what anyone can pour reliably, which is why no recipe has ever had to distinguish between them.
1.01 tsp
Five millilitres
the metric teaspoon
3.04 tsp
Fifteen millilitres
the metric tablespoon
4.06 tsp
Twenty millilitres
the Australian tablespoon
That third row is the one that catches people out. An Australian tablespoon is 20 millilitres, which is four teaspoons rather than the three everyone else uses. A recipe of Australian origin asking for a tablespoon is asking for a third more than an American or British one, and that gap is large enough to show.
Reading a metric label is the ordinary case. A 15 millilitre dose is three teaspoons or one tablespoon. A 30 millilitre measure is two tablespoons, which is also one fluid ounce. Once the ladder is in view, most metric quantities land on a spoon combination rather than needing a scale of their own.
- 2.5 mL
- 0.51 tsp, a half teaspoon
- 5 mL
- 1.01 tsp, one teaspoon
- 10 mL
- 2.03 tsp
- 15 mL
- 3.04 tsp, one tablespoon
- 30 mL
- 6.09 tsp, one fluid ounce
- 60 mL
- 12.17 tsp, a quarter cup
Each of these is within about one percent of a whole number of US spoons, which is why the two systems interchange so freely at kitchen scale.
When the metric figure is larger than a spoon
Past about 50 millilitres a jug beats a spoon. That page converts millilitres to US fluid ounces using the exact 29.5735295625 factor, and covers bottle and cabin-bag sizes.
Open the mL to oz converter →Millilitres converted to US teaspoons, with the nearest practical spoon measure alongside. The third column is what you would actually reach for.
| Millilitres | US teaspoons | What to measure |
|---|---|---|
| 1 mL | 0.20 tsp | a scant quarter teaspoon |
| 2.5 mL | 0.51 tsp | a half teaspoon |
| 5 mL | 1.01 tsp | one teaspoon |
| 7.5 mL | 1.52 tsp | a teaspoon and a half |
| 10 mL | 2.03 tsp | two teaspoons |
| 15 mL | 3.04 tsp | one tablespoon |
| 20 mL | 4.06 tsp | an Australian tablespoon |
| 25 mL | 5.07 tsp | a tablespoon and two teaspoons |
| 30 mL | 6.09 tsp | two tablespoons, one fluid ounce |
| 45 mL | 9.13 tsp | three tablespoons |
| 50 mL | 10.14 tsp | three tablespoons and a teaspoon |
| 75 mL | 15.22 tsp | five tablespoons |
| 100 mL | 20.29 tsp | a jug, not a spoon |
The direction that overfills
Converting teaspoons to millilitres and millilitres to teaspoons are not symmetric in their consequences. A US teaspoon holds 4.93 millilitres, so filling a 5 millilitre metric spoon and calling it a teaspoon delivers 1.44 percent more than the recipe asked for. Read the other way, using a US spoon for a metric measure delivers 1.44 percent less.
Neither matters once. Both matter in the same direction every time, because a rounding error does not alternate. Twenty teaspoons of liquid measured with metric spoons is about 1.4 millilitres over, which is a quarter of a spoon. The number only becomes visible once the count of spoonfuls climbs into the dozens.
- At 1 teaspoon
- 0.07 mL over, invisible
- At 3 teaspoons, one tablespoon
- 0.21 mL over
- At 12 teaspoons, a quarter cup
- 0.85 mL over
- At 48 teaspoons, one cup
- 3.41 mL over
- Where it starts to show
- never, in practice
Nobody measures a cup in teaspoons, and that is exactly why the substitution is safe. By the time the accumulated error reaches a visible size, the quantity has long since moved to a jug or a scale that does not care which spoon you own.
The practical rule is that spoons are for small quantities and the choice of spoon standard never decides a dish. What does decide one is mistaking a tablespoon for a teaspoon, an error of three hundred percent that the 1.44 percent question distracts from entirely.
Reading a dose in millilitres
Medicine labels increasingly give millilitres and nothing else, which is deliberate. The Institute for Safe Medication Practices lists both tsp and tbsp among its error-prone abbreviations because each can be misread as the other, and gives millilitres as the best practice for prescribing, dispensing and administering alike.
Where a label does say a teaspoon, it means 5 millilitres. Pharmaceutical practice settled on the round number rather than the 4.93 millilitre customary teaspoon, and any dropper, cup or spoon carrying a teaspoon mark is meant to deliver 5 millilitres at that mark. Approved labelling usually prints both, as one teaspoon, 5 mL.
- A metal kitchen teaspoon
- mean fell between 3.90 and 4.08 mL
- A calibrated medicine spoon
- mean fell between 4.91 and 5.09 mL
- An oral syringe
- mean fell between 5.09 and 5.17 mL
- Spread, metal spoon against syringe
- standard deviation 0.749 against 0.348 mL
- The device decides the dose
- not the unit
From Beckett and colleagues in Archives of Disease in Childhood, 2012. The kitchen spoon did not just read low, it read inconsistently. A separate survey of 71 household teaspoons found capacities from 2.5 to 7.3 millilitres, a spread the definitional question cannot touch.
So the answer to how many teaspoons a dose is has two halves. Arithmetically, 5 millilitres is 1.01 US teaspoons. Practically, the conversion is beside the point, because the instrument you reach for matters more than the unit the label is written in.
Every milliliters value, worked out
37 common milliliters figures each get their own page, with the answer at full precision, the arithmetic, what rounding costs, and the nearest real-world reference point on the scale.
Questions people ask
Sources
Where the constants and formulas on this page come from. Each line names the figure it backs.
The US teaspoon is one sixth of the US fluid ounce of exactly 29.5735295625 millilitres, giving 4.92892159375 mL.
NIST Guide to the SI, Appendix B.8 — Factors for units listed alphabetically — NIST
Measured capacities of 71 household teaspoons ranged from 2.5 to 7.3 mL with a mean of 4.4 mL.
Inaccuracies in dosing drugs with teaspoons and tablespoons — International Journal of Clinical Practice, 2010
Of 277 caregivers aiming at a 5 mL dose, the metal teaspoon group averaged between 3.90 and 4.08 mL with more than double the spread of an oral syringe.
Accurately administering oral medication to children isn't child's play — Archives of Disease in Childhood, 2012
The Australian tablespoon is specified as 20 mL, against 15 mL in New Zealand and most of the rest of the world.
AS 1325 — Kitchen utensils for measuring food ingredients — Standards Australia
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