Calcylator
Teaspoons to Millilitres

Teaspoons to ml:
multiply by 4.9289

Convert teaspoons to millilitres for spices, extracts and liquid measures, with a chart, worked examples and the mistakes that spoil recipes.

Calcylator Editorial Team

Updated · 5 min read

How many ml are in a teaspoon?

One US teaspoon is 4.928921594 millilitres, about 4.9 ml. It is one third of a US tablespoon and one sixth of a US fluid ounce.

Most cooks round it to 5 ml. That is the figure on many measuring spoon sets, and it is off by only 1.4 percent, so for vanilla, baking powder or cinnamon the rounding is harmless.

The tsp to ml formula

US teaspoons to millilitres =ml = tsp × 4.928921594
ml:
volume in millilitres
tsp:
volume in US teaspoons
4.928921594:
millilitres in one US teaspoon
To go back, multiply ml by 0.2028841362 to get teaspoons.

  • Volume

    2 tsp

  • Multiply

    2 × 4.928921594

Volume in ml

9.86 ml

The full result is 9.857843188 ml, just under 10 ml.

A fast check is to multiply by 5. Two teaspoons gives 10 ml, and the exact answer should always come out a little lower.

  1. Write the spoon count as a decimal (1/4 tsp is 0.25).
  2. Multiply by 4.928921594.
  3. Round to one decimal place for small amounts.
  4. Check against tsp × 5; the exact answer should be slightly smaller.

Chart: teaspoons to ml from 1 to 1000

The chart lists exact values. For kitchen use, one decimal place is plenty.

US teaspoons to millilitres
TeaspoonsMillilitres
14.928921594
29.857843188
524.64460797
1049.28921594
25123.2230398
50246.4460797
100492.8921594
2501232.230398
5002464.460797
10004928.921594

Notice that 50 teaspoons is only 246 ml, a little more than one US cup, which shows how small a single teaspoon really is.

Where teaspoon to ml conversions come up

A quarter teaspoon of salt sounds tiny, but in millilitres it is 0.25 × 4.928921594 = 1.23 ml, which is the sort of amount you would measure with a dropper rather than a jug.

A recipe that asks for 15 teaspoons of cocoa for a large batch needs 15 × 4.928921594 = 73.93 ml, close to a third of a cup. Going backwards, 100 ml of syrup is 100 × 0.2028841362 = 20.29 teaspoons.

For liquid medicine, do not use a kitchen teaspoon at all. Follow the label and use the syringe or cup that came with the product, since household spoons vary in size.

Common mistakes when converting tsp to ml

  • Confusing tsp with tbsp. A tablespoon is three teaspoons, so swapping them triples or cuts by a third.
  • Using the wrong spoon size. A US teaspoon is 4.93 ml, a metric one is exactly 5 ml, and a cutlery teaspoon can hold more or less than either.
  • Measuring heaped instead of level. A level spoon is the standard, and a heaped one can hold much more, especially of powders.
  • Rounding too early. Convert the whole count first, then round, because 12 rounded teaspoons add up to a visible error.

Common questions

How many ml is 1 teaspoon?

One US teaspoon is 4.928921594 ml, about 4.9 ml. Many recipes round this to 5 ml, which is the metric teaspoon. The two differ by less than 0.1 ml, so you can use either one for cooking and baking.

How do I convert tsp to ml?

Multiply the teaspoons by 4.928921594. For example, 3 tsp is 3 × 4.928921594 = 14.79 ml. As a rough check, multiply by 5, which gives 15 ml for three teaspoons, slightly above the exact answer.

How many teaspoons are in 100 ml?

There are about 20.3 US teaspoons in 100 ml, found by multiplying 100 by 0.2028841362. With the 5 ml rule you would get exactly 20, so the quick estimate is close but slightly low.

Is a teaspoon 5 ml or 4.93 ml?

A US teaspoon is 4.93 ml and a metric teaspoon is 5 ml. Both are accepted for kitchen use and differ by about 1.4 percent. Use 4.93 ml when you want the exact US figure, and 5 ml for convenience.

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