What is a Teaspoon?

The teaspoon equals exactly 5 milliliters (international culinary standard) or about 4.929 mL (US strict definition based on 1/3 of a tablespoon). The teaspoon is the smallest standard cooking measure, used worldwide for spices, baking soda, vanilla extract, salt, and small ingredient quantities. A flat (level) teaspoon is the recipe convention; rounded or heaping teaspoons are inconsistent and avoided in serious cooking. The teaspoon is also a medical unit: many liquid medications are dosed in teaspoons (5 mL standard). The teaspoon relates to the tablespoon (1 tbsp = 3 tsp), the cup (48 tsp = 1 cup), the milliliter (1 tsp = 5 mL conventional), and the fluid ounce (6 tsp = 1 fl oz). Standardized 5-mL measuring spoons are available globally to avoid the variability of household teaspoons (which range from 2 to 7 mL).

Visual reference for how the teaspoon relates to other volume units. Each row links to the full converter for that pair.

See all 15 volume units in matrix view →

• Baking powder, salt and spices in recipes
• Over-the-counter liquid-medicine dosing
• Coffee and tea sweetener measurements

• ✓1 tsp = 5 ml (practical); 4.929 ml (US legal).
• ✓3 tsp = 1 tbsp universally.
• ✓Use a proper measuring spoon — household teaspoons vary 3–8 ml.

• ✗Using a regular cutlery teaspoon for medication — can over- or under-dose by 30–60%.
• ✗Mixing tsp and tbsp — 3× difference.
• ✗Assuming "a pinch" or "a dash" is reproducible — it varies 0.1 to 0.5 ml.