Convert US Teaspoon to Millilitre
1 us teaspoon = 4.928922 millilitre (mL). For example, 10 us teaspoon = 49.28922 millilitre and 100 us teaspoon = 492.8922 millilitre. Type any value below to convert us teaspoon to millilitre both ways — it runs entirely in your browser.
Quick answer: US Teaspoon to Millilitre
1 US Teaspoon = 4.928922 Millilitre (tsp → mL). To convert us teaspoon to millilitre, multiply by 4.928922. To convert millilitre to us teaspoon, multiply by 0.2028841. The converter at the top does this instantly and both ways; the sections below give the formula, worked examples, a full conversion chart and answers to the most common us teaspoon-to-millilitre questions.
How to convert US Teaspoon to Millilitre
To convert us teaspoon to millilitre, multiply the number of us teaspoon by the conversion factor 4.928922, because 1 tsp = 4.928922 mL. The conversion is linear, so the same factor works for any value — whole numbers, decimals or fractions. For the reverse direction, 1 mL = 0.2028841 tsp, so you divide by 4.928922 (or multiply by 0.2028841) to turn millilitre back into us teaspoon.
mL = tsp × 4.928922 ·
tsp = mL × 0.2028841
- Write down the value you want to convert, in us teaspoon.
- Multiply it by 4.928922.
- The result is the same area/length/quantity expressed in millilitre.
US Teaspoon to Millilitre — worked examples
Each row shows the exact arithmetic so you can follow the conversion step by step. For example, 5 us teaspoon is 24.64461 millilitre because 5 tsp × 4.928922 = 24.64461 mL.
| US Teaspoon | Calculation | Millilitre |
|---|---|---|
| 1 tsp | 1 tsp × 4.928922 = 4.928922 mL | 4.928922 mL |
| 2 tsp | 2 tsp × 4.928922 = 9.857843 mL | 9.857843 mL |
| 3 tsp | 3 tsp × 4.928922 = 14.78676 mL | 14.78676 mL |
| 5 tsp | 5 tsp × 4.928922 = 24.64461 mL | 24.64461 mL |
| 7 tsp | 7 tsp × 4.928922 = 34.50245 mL | 34.50245 mL |
| 10 tsp | 10 tsp × 4.928922 = 49.28922 mL | 49.28922 mL |
| 12 tsp | 12 tsp × 4.928922 = 59.14706 mL | 59.14706 mL |
| 15 tsp | 15 tsp × 4.928922 = 73.93382 mL | 73.93382 mL |
| 20 tsp | 20 tsp × 4.928922 = 98.57843 mL | 98.57843 mL |
| 25 tsp | 25 tsp × 4.928922 = 123.223 mL | 123.223 mL |
| 50 tsp | 50 tsp × 4.928922 = 246.4461 mL | 246.4461 mL |
| 100 tsp | 100 tsp × 4.928922 = 492.8922 mL | 492.8922 mL |
Common US Teaspoon to Millilitre conversions
These are the us teaspoon-to-millilitre values people look up most often. Every figure is computed from the exact factor, so you can rely on them for quick reference:
- 1 us teaspoon = 4.928922 millilitre
- 2 us teaspoon = 9.857843 millilitre
- 2.5 us teaspoon = 12.3223 millilitre
- 3 us teaspoon = 14.78676 millilitre
- 4 us teaspoon = 19.71569 millilitre
- 5 us teaspoon = 24.64461 millilitre
- 6 us teaspoon = 29.57353 millilitre
- 7 us teaspoon = 34.50245 millilitre
- 8 us teaspoon = 39.43137 millilitre
- 9 us teaspoon = 44.36029 millilitre
- 10 us teaspoon = 49.28922 millilitre
- 12 us teaspoon = 59.14706 millilitre
- 15 us teaspoon = 73.93382 millilitre
- 20 us teaspoon = 98.57843 millilitre
- 25 us teaspoon = 123.223 millilitre
- 30 us teaspoon = 147.8676 millilitre
- 50 us teaspoon = 246.4461 millilitre
- 75 us teaspoon = 369.6691 millilitre
- 100 us teaspoon = 492.8922 millilitre
- 200 us teaspoon = 985.7843 millilitre
- 500 us teaspoon = 2,464.461 millilitre
- 1000 us teaspoon = 4,928.922 millilitre
US Teaspoon to Millilitre conversion chart (both directions)
The chart below converts us teaspoon to millilitre and millilitre to us teaspoon side by side, so it works whichever way you need. 1 us teaspoon = 4.928922 millilitre, and 1 millilitre = 0.2028841 us teaspoon.
| US Teaspoon → Millilitre | Millilitre → US Teaspoon |
|---|---|
| 0.25 tsp = 1.23223 mL | 0.25 mL = 0.05072103 tsp |
| 0.5 tsp = 2.464461 mL | 0.5 mL = 0.1014421 tsp |
| 1 tsp = 4.928922 mL | 1 mL = 0.2028841 tsp |
| 2 tsp = 9.857843 mL | 2 mL = 0.4057683 tsp |
| 3 tsp = 14.78676 mL | 3 mL = 0.6086524 tsp |
| 4 tsp = 19.71569 mL | 4 mL = 0.8115365 tsp |
| 5 tsp = 24.64461 mL | 5 mL = 1.014421 tsp |
| 6 tsp = 29.57353 mL | 6 mL = 1.217305 tsp |
| 7 tsp = 34.50245 mL | 7 mL = 1.420189 tsp |
| 8 tsp = 39.43137 mL | 8 mL = 1.623073 tsp |
| 9 tsp = 44.36029 mL | 9 mL = 1.825957 tsp |
| 10 tsp = 49.28922 mL | 10 mL = 2.028841 tsp |
| 12 tsp = 59.14706 mL | 12 mL = 2.43461 tsp |
| 15 tsp = 73.93382 mL | 15 mL = 3.043262 tsp |
| 20 tsp = 98.57843 mL | 20 mL = 4.057683 tsp |
| 25 tsp = 123.223 mL | 25 mL = 5.072103 tsp |
| 30 tsp = 147.8676 mL | 30 mL = 6.086524 tsp |
| 40 tsp = 197.1569 mL | 40 mL = 8.115365 tsp |
| 50 tsp = 246.4461 mL | 50 mL = 10.14421 tsp |
| 75 tsp = 369.6691 mL | 75 mL = 15.21631 tsp |
| 100 tsp = 492.8922 mL | 100 mL = 20.28841 tsp |
| 150 tsp = 739.3382 mL | 150 mL = 30.43262 tsp |
| 200 tsp = 985.7843 mL | 200 mL = 40.57683 tsp |
| 250 tsp = 1,232.23 mL | 250 mL = 50.72103 tsp |
| 500 tsp = 2,464.461 mL | 500 mL = 101.4421 tsp |
| 1000 tsp = 4,928.922 mL | 1000 mL = 202.8841 tsp |
US Teaspoon vs Millilitre: which is bigger?
A us teaspoon is the larger unit: one us teaspoon equals 4.928922 millilitres. Put another way, you need 4.928922 millilitres to make a single us teaspoon.
What is a US Teaspoon? History, origin and usage
The teaspoon began as the small spoon used to stir tea, which arrived in England in the 1600s, and its size grew as tea became cheaper and teacups larger through the early 1700s. It was eventually standardised at one third of a tablespoon, the proportion still used in the US customary system.
The teaspoon is the standard small measure for baking powder, salt, vanilla, spices and other potent ingredients in cooking. It is also a familiar dose marker for liquid medicines, though health authorities prefer proper millilitre measuring for medication.
A US teaspoon is one sixth of a fluid ounce and one third of a tablespoon, a tidy ratio that makes scaling recipes easy. Using an ordinary tea-drinking spoon instead of a measuring teaspoon is a common source of inaccurate baking.
What is a Millilitre? History, origin and usage
The millilitre is the litre scaled by the metric prefix milli- (Latin mille, a thousandth), so it inherits the litre's origin in the 1795 French metric reforms. Because the litre was defined in relation to the metre, the millilitre became exactly one cubic centimetre when the litre was tied to the cubic decimetre. It has been part of the coherent metric vocabulary ever since the SI prefixes were standardised.
The millilitre is the workhorse small-volume unit almost everywhere outside the United States: medicine doses, syringes and IV bags, drink and food nutrition labels, perfume and cosmetics, and home cooking. Laboratories and pharmacies use it constantly for measuring liquids. In medicine the equivalent term cubic centimetre (cc) is still heard, especially for syringes.
One millilitre is identical in volume to one cubic centimetre, because a litre is exactly one cubic decimetre. A standard metric teaspoon is taken as five millilitres, which is why liquid-medicine dosing cups are graduated in millilitres rather than spoons.
Convert 1 US Teaspoon to other units
It can help to see a us teaspoon next to the other units it is commonly compared with. One us teaspoon (tsp) is equal to:
| 1 US Teaspoon equals | Unit |
|---|---|
| 4.928922 mL | Millilitre |
| 0.4928922 cL | Centilitre |
| 0.004928922 L | Litre |
| 0.000004928922 m³ | Cubic Metre |
| 4.928922 cm³ | Cubic Centimetre |
| 0.3007813 in³ | Cubic Inch |
| 0.0001740632 ft³ | Cubic Foot |
| 0.001302083 US gal | US Gallon |
| 0.001302083 gal | US Gallon |
| 0.005208333 US qt | US Quart |
| 0.005208333 qt | US Quart |
| 0.01041667 US pt | US Pint |
| 0.01041667 pt | US Pint |
| 0.1666667 US fl oz | US Fluid Ounce |
| 0.1666667 fl oz | US Fluid Ounce |
| 0.1734738 imp fl oz | Imperial Fluid Ounce |
| 0.3333333 tbsp | US Tablespoon |
| 0.04166667 gi | US Gill |
| 0.0001398709 bu | US Bushel |
| 0.00003100198 bbl | Oil Barrel |
| 4,928.922 µL | Microlitre |
| 0.02083333 US cup | US Cup |
| 0.1666667 US fl oz | US Fluid Ounce |
Convert 1 Millilitre to other units
One millilitre (mL) is equal to:
| 1 Millilitre equals | Unit |
|---|---|
| 0.1 cL | Centilitre |
| 0.001 L | Litre |
| 0.000001 m³ | Cubic Metre |
| 1 cm³ | Cubic Centimetre |
| 0.06102374 in³ | Cubic Inch |
| 0.00003531467 ft³ | Cubic Foot |
| 0.0002641721 US gal | US Gallon |
| 0.0002641721 gal | US Gallon |
| 0.001056688 US qt | US Quart |
| 0.001056688 qt | US Quart |
| 0.002113376 US pt | US Pint |
| 0.002113376 pt | US Pint |
| 0.03381402 US fl oz | US Fluid Ounce |
| 0.03381402 fl oz | US Fluid Ounce |
| 0.03519508 imp fl oz | Imperial Fluid Ounce |
| 0.06762805 tbsp | US Tablespoon |
| 0.2028841 tsp | US Teaspoon |
| 0.008453506 gi | US Gill |
| 0.00002837759 bu | US Bushel |
| 0.000006289811 bbl | Oil Barrel |
| 1,000 µL | Microlitre |
| 0.004226753 US cup | US Cup |
| 0.03381402 US fl oz | US Fluid Ounce |
Tips for converting US Teaspoon to Millilitre
- To go from us teaspoon to millilitre, multiply by 4.928922; to go back, divide by 4.928922 (or multiply by 0.2028841).
- For a quick mental estimate, remember that 1 us teaspoon ≈ 4.928922 millilitre, so 10 us teaspoon ≈ 49.28922 millilitre.
- The converter above keeps full precision; the tables round for readability, so use the tool for exact figures.
- Both fields update live as you type — change either side to convert in that direction.
How to use this US Teaspoon to Millilitre converter
Type a number into the US Teaspoon field and the equivalent in Millilitre appears instantly — there is no “convert” button to press and nothing is sent to a server, so it works offline once the page has loaded and is safe for any data. You can also type into the Millilitre field to convert the other way (millilitre to us teaspoon). Use the swap control to flip the two units, and copy the result with a single click. Because the calculation runs in your browser with full floating-point precision, the converter is more exact than the rounded figures shown in the reference chart above — use the chart for quick look-ups and the tool for precise work.
Accuracy and method
Every figure on this page — the formula, the worked examples, the conversion chart and the “convert to other units” tables — is computed from a single verified conversion factor (1 tsp = 4.928922 mL), never copied from a hand-typed lookup table that could drift. That factor is derived from each unit’s definition in terms of a common base unit, and an automated check re-verifies all of the site’s factors on every update, so the numbers here stay correct over time. This matters for us teaspoon-to-millilitre conversions because a small rounding error in a published table compounds quickly at larger quantities; computing from the exact factor avoids that.
Sources
- NIST Special Publication 811 — Guide for the Use of the SI — publishes the exact metric equivalents of the customary units. The inch, foot, yard and mile are defined exactly in metres by the 1959 international yard-and-pound agreement, so every imperial figure on this page is exact, not rounded.
- BIPM — The International System of Units (SI Brochure) — the defining document for the SI, published by the International Bureau of Weights and Measures. It fixes the base unit that this conversion resolves to, which is why the factor here can be exact rather than approximate.
Watch the system: a <strong>US</strong> gallon, quart, pint and fluid ounce are <strong>not</strong> the same size as the <strong>imperial (UK)</strong> ones — a US gallon is 3.785 L while an imperial gallon is 4.546 L, and a US fluid ounce (29.57 mL) is slightly larger than an imperial fluid ounce (28.41 mL). The units on this page are labelled US or Imperial so the result is unambiguous.
Frequently asked questions
- How many millilitre are in 1 us teaspoon?
- 1 us teaspoon = 4.928922 millilitre (mL). To convert any number of us teaspoon to millilitre, multiply by 4.928922.
- How do I convert us teaspoon to millilitre?
- Multiply the number of us teaspoon by 4.928922. For example, 10 us teaspoon = 10 × 4.928922 = 49.28922 millilitre, and 25 us teaspoon = 123.223 millilitre.
- How many us teaspoon are in 1 millilitre?
- 1 millilitre = 0.2028841 us teaspoon. So to convert millilitre back to us teaspoon, multiply by 0.2028841.
- What is the formula to convert us teaspoon to millilitre?
- millilitre = us teaspoon × 4.928922. The reverse formula is us teaspoon = millilitre × 0.2028841.
- How much is 100 us teaspoon in millilitre?
- 100 us teaspoon = 492.8922 millilitre. (And 1000 us teaspoon = 4,928.922 millilitre.)
- Which is bigger, a us teaspoon or a millilitre?
- A us teaspoon is larger: 1 us teaspoon = 4.928922 millilitre.
- Is this us teaspoon to millilitre converter accurate?
- Yes — every value is computed from the exact 4.928922 mL per tsp factor (not rounded look-up tables), and the factors are re-verified automatically on every update.
- Can I convert millilitre to us teaspoon too?
- Yes. The converter works both ways — enter a value in either field. 1 millilitre = 0.2028841 us teaspoon.