Dr. David Taylor, MD, PhD · Last reviewed July 24, 2026

Teaspoon to mL Converter

Type teaspoons or milliliters in either box and the other updates instantly. Switch between the metric teaspoon (5 mL — the standard on medicine and nutrition labels) and the US customary kitchen teaspoon (4.93 mL). When your value is a liquid-medicine dose, you'll see how to measure it. Free, no signup, reviewed by a physician.

Teaspoon to Milliliter Converter

Teaspoon type
tsp
mL

Educational reference only — this converts units, it is not a dosing calculator. Never set or change a medicine dose from a conversion. Follow the product label or your clinician or pharmacist, and measure liquid medicine with the syringe or cup that came with it — a kitchen teaspoon is not a reliable dose.

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How to use this converter

  1. Type in either box. Enter teaspoons and the milliliters update live — or type milliliters and teaspoons fill in. There's no Calculate button; the math runs as you type.
  2. Pick the teaspoon type. Leave it on Metric · 5 mL for medicine and nutrition labels (this is what a medicine "teaspoonful" means). Switch to US customary · 4.93 mL for recipes and kitchen measuring.
  3. Use a preset. The chips fill in the amounts people actually measure: ¼, ½, 1, and 1½ teaspoons, and 1 tablespoon (3 teaspoons).
  4. Read the dosing note — if it's medicine. When your value lands in liquid-medicine range, a card shows the nearest common dose and whether to use an oral syringe or a dosing cup. For larger cooking volumes you'll see a plain kitchen reference instead.
  5. Copy, share, or print. Copy the conversion, grab a link that reopens this exact value, or download a one-page printable tsp↔mL dosing chart.

Why this converter is different from other teaspoon-to-mL pages

Most teaspoon-to-milliliter converters online do one thing: turn a number on one scale into a number on the other. That's fine until the reason you're converting is a bottle of liquid medicine and you actually need to measure a dose safely. Here's what this tool adds:

  • Both teaspoon definitions, side by side. A US kitchen teaspoon is 4.93 mL; the "teaspoon" used on medicine and nutrition labels is exactly 5 mL. Most pages pick one and leave you guessing which — this one shows both for every value.
  • A dosing reference built in. When the amount is a liquid-medicine dose, you get the nearest common dose and the right measuring device — an oral syringe under 5 mL, a dosing cup above it. No general converter does this.
  • The safety fact nobody prints. A real kitchen teaspoon holds anywhere from 2.5 to 7 mL, which is why the FDA and pediatricians say never to dose liquid medicine with a household spoon. This tool says so, at the moment you need it.
  • A printable chart, not a static PDF. Download a clean, current tsp↔mL chart with the common-dose reference built in.
  • Embeddable and physician-reviewed. Clinics, school nurses, and parenting sites can drop the live converter onto their own page in one line. Reviewed by Dr. David Taylor, MD, PhD, with the math shown openly.

How the conversion works (the math)

A teaspoon and a milliliter are both units of volume, so converting is a single multiply-or-divide — the only question is which teaspoon:

mL = teaspoons × 5  (metric / medicine & label standard)
mL = teaspoons × 4.92892  (US customary kitchen teaspoon)
teaspoons = mL ÷ 5  (or ÷ 4.92892 for US customary)

The metric teaspoon is defined as exactly 5 mL, and that's the value the U.S. FDA uses for over-the-counter drug labeling — when a label says "one teaspoonful," it means 5 mL, full stop. The US customary teaspoon works out to 4.92892 mL (one-third of a US tablespoon), which is what recipes assume. The two are close enough that for cooking the difference never matters, but they are not identical, which is exactly why medicine is dosed in millilitres, not spoons. Unit definitions come from NIST; the 5 mL teaspoonful is the FDA labeling convention.

Worked examples

How many mL is a teaspoon of medicine?

Exactly 5 mL. Every medicine label that says "1 teaspoonful" means 1 × 5 = 5 mL — it is not referring to whatever spoon is in your drawer. If your cough syrup or children's allergy liquid came with an oral syringe or a marked cup, use it and read the mL line.

What is half a teaspoon in mL?

0.5 × 5 = 2.5 mL. Half a teaspoon is 2.5 mL, a very common children's dose. At that size an oral syringe is far more accurate than any spoon — 2.5 mL simply doesn't read reliably on a teaspoon.

Is a tablespoon of an antacid the same as three teaspoons?

Yes. One tablespoon is 3 × 5 = 15 mL. Adult liquid antacids and some laxatives are dosed at 15–30 mL; measure those in the cup that came with the bottle rather than counting spoonfuls.

Teaspoon to mL reference chart

The everyday range at a glance, with both teaspoon definitions. Rows in the common liquid-medicine range are highlighted.

Teaspoons mL (metric, 5 mL) mL (US customary) Notes
1/4 tsp 1.25 mL 1.23 mL Small dose — use an oral syringe
1/2 tsp 2.5 mL 2.46 mL Common children's dose
3/4 tsp 3.75 mL 3.7 mL
1 tsp 5 mL 4.93 mL One 'teaspoonful' on a medicine label = 5 mL
1 1/2 tsp 7.5 mL 7.39 mL
2 tsp 10 mL 9.86 mL
3 tsp 15 mL 14.79 mL = 1 tablespoon
4 tsp 20 mL 19.72 mL
6 tsp 30 mL 29.57 mL = 2 tablespoons / 1 fl oz

Frequently asked questions

Is 1 teaspoon equal to 5 mL?

For medicine and nutrition labels, yes — a teaspoonful is defined as exactly 5 mL. The strict US customary kitchen teaspoon is a touch smaller at 4.93 mL, but the 5 mL figure is the one that matters whenever you're measuring a dose.

How many mL is a teaspoon of medicine?

5 mL. When a medicine label says "1 teaspoonful," it means 5 mL regardless of the spoons in your kitchen. For accuracy, use the oral syringe or dosing cup supplied with the product rather than a household spoon.

Is 1 teaspoon 2.5 mL?

No — 2.5 mL is half a teaspoon. A full teaspoon is 5 mL. The 2.5 mL mix-up is common because many children's doses are exactly half a teaspoon, which is where an oral syringe helps.

Why shouldn't I use a kitchen teaspoon for medicine?

Because "teaspoon" spoons vary a lot — real ones hold anywhere from about 2.5 to 7 mL. Studies behind the FDA's guidance found that dosing liquid medicine with household spoons leads to frequent under- and over-doses, especially for children. Use the marked syringe or cup and read the mL amount.

Can I embed this converter on my own site?

Yes — copy the snippet at the bottom of this page. The embedded version is a stripped-down converter built for clinics, school-nurse pages, and parenting or recipe blogs. Required attribution is included; there's no fee, signup, or tracking attached.

A converter tells you that a teaspoonful is 5 mL; measuring it accurately is the other half. If a liquid-medicine dose sent you here, these are the categories worth getting right:

Sources & methodology

The conversion is a fixed unit relationship and does not change; this page is reviewed annually for citation currency. About Dr. Taylor · Last reviewed July 24, 2026.

Cite this page

Free to cite or link in coursework, handouts, and articles — no permission needed.

Taylor, D. (2026, July 24). Teaspoon to mL Converter. BestRatedDocs. https://bestrateddocs.com/teaspoon-to-ml-converter/

Embed this tool on your site

Free for clinics, school-nurse pages, pharmacies, and parenting or recipe blogs. Required attribution is included in the snippet. No fee, no signup, no tracking attached to the embed. 

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