1 Teaspoon to mL
Exactly how many milliliters are in 1 teaspoon? 1 US teaspoon = 4.92892 mL, with a quick reference table for other spoon measures.
1 Teaspoon to mL: The Quick Answer
1 teaspoon (1 tsp) converts to 4.93 mL. Whether you are reading a metric label, a recipe, or an international spec, knowing how to convert 1 teaspoon (1 tsp) keeps your numbers consistent. Use our teaspoons to ml converter for any value, or read on for the full breakdown of the 4.93 mL result.
The Exact Teaspoons to Milliliters Formula
A US teaspoon is 1/3 of a US fluid ounce. Since 1 fl oz = 29.5735 mL, 1 tsp = 4.9289 mL exactly. To convert teaspoons to milliliters, multiply the teaspoons by 4.9289.
Step-by-Step Calculation
Start with 1 tsp. Multiply by 4.9289: 1 x 4.9289 = 4.9289 mL, which rounds to 4.93 mL.
A Quick Mental Estimate
Because 1 tsp is just under 5 mL, rounding to 5 mL works for casual cooking and is only about 0.07 mL high.
Where 1 teaspoon (1 tsp) Comes Up
The teaspoon is the small workhorse of US recipes and medicine: a quarter-teaspoon of salt, a teaspoon of vanilla, or a 5 mL cough-medicine scoop all hover around this size. Knowing 1 tsp = 4.93 mL lets you use a metric spoon or syringe instead of guessing.
1 teaspoon (1 tsp) Compared With Nearby Values
Nearby spoon amounts: 0.5 tsp = 2.46 mL, 2 tsp = 9.86 mL.
On the other side, 3 tsp = 14.79 mL, 4 tsp = 19.72 mL. Each step moves the figure smoothly, so the same formula scales to any amount.
Practical Uses of the 1 teaspoon (1 tsp) Conversion
Reach for this conversion when a metric recipe lists milliliters of an extract or spice, or when a medicine cup marks 5 mL doses. Our teaspoons to mL converter does the math for any amount, and tablespoons to mL covers the larger spoon (3 tsp = 1 tbsp).
Frequently Asked Questions
How many mL is 1 teaspoon?
1 US teaspoon = 4.92892 mL (about 4.93 mL).
How many teaspoons in a tablespoon?
3 teaspoons = 1 tablespoon = 14.7868 mL.
How many mL is half a teaspoon?
0.5 tsp × 4.92892 = 2.46446 mL.
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Quick Summary
1 teaspoon (1 tsp) equals 4.93 mL. Use the teaspoons to milliliters relationship shown above for exact, repeatable results.
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Disclaimer
Unit conversions on this site use internationally recognized, fixed conversion factors (for example, 1 inch = 2.54 cm, 1 pound = 0.45359237 kg, 1 °F = (°C × 9/5) + 32). They are provided for general, informational, and educational use. For applications where accuracy is critical — such as medical dosing, engineering, scientific research, trade, or legal compliance — always verify results against authoritative sources such as the U.S. National Institute of Standards and Technology (NIST) and the official International System of Units (SI) brochure, and follow any applicable local standards.
Exact Constants & Authoritative Sources
Every conversion on this page uses the fixed, internationally agreed constants below — drawn from NIST and the SI Brochure. No values are estimated or rounded as if exact. See the full list on our Sources & Standards page.
- EXACT1 US gallon (gal) = 3.785411784 litres (exact, 231 in³)
- EXACT1 US fluid ounce (fl oz) = 29.5735295625 mL (exact, 1/128 gal)
- EXACT1 US cup = 236.5882365 mL (exact, 8 fl oz)
- EXACT1 US pint (pt) = 473.176473 mL (exact, 16 fl oz)
- EXACT1 US quart (qt) = 946.352946 mL (exact, 32 fl oz)
- EXACT1 litre (L) = 1000 millilitres (definition)
Common Pitfalls & How to Avoid Them
US vs. Imperial (UK) cups
A US cup is 236.59 mL, but a UK/metric cup is 250 mL and an Imperial cup is ~284 mL. Recipes from different countries are not interchangeable drop-in.
Fluid ounce is volume, not mass
A US fl oz is 29.57 mL of volume. 1 fl oz of water ≈ 29.57 g, but 1 fl oz of honey or oil weighs more. Do not treat fluid ounces as grams.
Teaspoon/tablespoon sizes differ
1 US tbsp = 14.7868 mL; 1 US tsp = 4.92892 mL. Metric measuring spoons are 15 mL and 5 mL — close but not exact; for baking precision use weighed grams.
A unit-conversion reference site has no manufacturer-specific or device calibration parameters, so "layered tuning" does not apply here. The only real error-handling is input validation: the converter rejects non-numeric, empty, or out-of-range entries and shows a clear message, then falls back to exact constants above. No estimated or rounded figures are ever presented as exact.
Authoritative sources for this page
- NIST (U.S. National Institute of Standards and Technology) — NIST SP 330 — The International System of Units (SI), 2019 edition
- BIPM (International Bureau of Weights and Measures) — SI Brochure — The International System of Units (9th edition)
Last Updated 2026 | This article was reviewed for accuracy