About this Teaspoon ⇄ Milliliter Calculator

This tool converts between teaspoons and milliliters instantly, using precise, industry-standard factors. It supports both the US customary teaspoon and the metric teaspoon so you get accurate results whether you’re cooking, dosing medicine, or scaling a recipe.

Quick reference

1 US teaspoon (tsp) = 4.92892159375 mL, this calculator uses that exact factor for conversions.

Which “teaspoon” is which?

There are two common standards: the US customary teaspoon and the metric teaspoon. The metric teaspoon is typically treated as exactly 5 mL, while the US teaspoon is slightly smaller at about 4.9289 mL. Recipes and medicine instructions may use either, so it’s important to confirm which one is intended.

How the conversion works

Converting is straightforward:
value_in_mL = value_in_tsp × factor (for example, using US tsp: multiply by 4.92892159375).
To go the other way: value_in_tsp = value_in_mL ÷ factor. The calculator runs these operations and formats the result to a sensible number of decimal places for display.

Examples

• 1 US tsp → 4.92892159375 mL.
• 1 metric tsp → 5 mL.
• 15 US tsp → 73.93382390625 mL (15 × 4.92892159375).

Practical measuring tips (for the kitchen and pharmacy)

• For cooking: Liquid teaspoons are approximate when measured with cutlery use a proper measuring spoon or a syringe/measuring cup for best repeatability. The Exploratorium’s measurement guides explain how small differences can change results in delicate recipes.
• For medicine: Never substitute a household teaspoon for a dosing device. Pediatric doses must be exact; use an oral syringe or calibrated dosing cup and follow the prescription or label carefully. If you’re unsure, confirm the measurement device and units with a pharmacist or clinician.
• Rounding: For recipes a rounded value (e.g., 5 mL for a metric tsp) is usually fine; for medical or laboratory use prefer more precise numbers and the correct measuring instruments.

Common equivalents

• 3 teaspoons = 1 tablespoon (US customary).
• 1 tablespoon (US) = 14.7867647813 mL (so 1 tbsp ≈ 3 × 4.9289 mL).
• 1 metric teaspoon = 5 mL exactly.

Conversion table

Teaspoons (US)	Milliliters
0.25 tsp	1.2322303984 mL
0.5 tsp	2.4644607969 mL
1 tsp	4.9289215938 mL
2 tsp	9.8578431875 mL
3 tsp	14.7867647813 mL
10 tsp	49.2892159375 mL

Why small differences matter

The tiny discrepancy between US and metric teaspoons (≈0.07108 mL) rarely affects hearty recipes, but it can matter for precise bakes, lab work, or pediatric dosing. When accuracy is required, always use the unit specified, this calculator makes those conversions explicit so you can avoid guesswork.

FAQs

Q1. Can I use a kitchen teaspoon for medicine?

A: No,kitchen spoons vary and are not precise enough for dosing. Use the measuring device provided with the medication or ask your pharmacist.

Q2. Which teaspoon should I assume in recipes?

A: Many modern recipes assume metric teaspoons (5 mL) outside the US; check the recipe source or context. When in doubt, use the calculator and state which teaspoon you mean.

Q3. Can I switch to tablespoons or cups?

A: Yes, this calculator supports other volume units (tablespoons, centiliters, liters, cups). Use the unit selectors to convert cleanly and avoid manual arithmetic.