Teaspoons to Milliliters: Cooking and Medicine Guide for Americans
Published on June 24, 2026 · 8 min read
Your child's pediatrician prescribes 7.5 ml of liquid medication — but the only measuring tool you have is a teaspoon. A British recipe calls for 5 ml of vanilla extract and you reach for your measuring spoons. A European supplement says take 15 ml per day and you need to know how many tablespoons that is. Teaspoons and milliliters cross paths constantly in the kitchen and medicine cabinet. This guide makes the conversion instant.
The Exact Formula
1 US teaspoon = 4.92892 ml (exact)
Milliliters = Teaspoons × 4.92892
Teaspoons = Milliliters ÷ 4.92892
For everyday use: 1 teaspoon ≈ 5 ml. This is so close (error of 1.4%) that doctors, pharmacists, and recipe writers worldwide use it as the standard equivalence. In medicine, 5 ml = 1 teaspoon is official.
All Spoon Sizes: Complete Reference
| US Measurement | Milliliters (exact) | Milliliters (approx) |
|---|---|---|
| ⅛ teaspoon | 0.616 ml | 0.6 ml |
| ¼ teaspoon | 1.232 ml | 1.25 ml |
| ½ teaspoon | 2.464 ml | 2.5 ml |
| ¾ teaspoon | 3.696 ml | 3.7 ml |
| 1 teaspoon | 4.929 ml | 5 ml |
| 1½ teaspoons | 7.393 ml | 7.5 ml |
| 2 teaspoons | 9.858 ml | 10 ml |
| 1 tablespoon (3 tsp) | 14.787 ml | 15 ml |
| 2 tablespoons | 29.574 ml | 30 ml |
| ¼ cup (4 tbsp) | 59.147 ml | 60 ml |
| ⅓ cup | 78.863 ml | 79 ml |
| ½ cup | 118.294 ml | 120 ml |
| 1 cup | 236.588 ml | 240 ml |
Medicine: Liquid Dosing in ml vs Teaspoons
The FDA recommends that liquid medications always be measured in milliliters — not teaspoons — because household spoons vary in size by up to 20%. However, many labels still show both. Here are the common medical doses translated:
| ml Dose | Teaspoon Equivalent | Common Use |
|---|---|---|
| 1.25 ml | ¼ tsp | Infant drops (small dose) |
| 2.5 ml | ½ tsp | Infant/toddler dose |
| 3.75 ml | ¾ tsp | Child dose (small) |
| 5 ml | 1 tsp | Standard child dose |
| 7.5 ml | 1½ tsp | Child dose (larger) |
| 10 ml | 2 tsp | Standard adult dose (liquid) |
| 15 ml | 1 tbsp | Adult dose (larger / cough syrup) |
| 20 ml | 4 tsp | Large adult dose |
| 30 ml | 2 tbsp (6 tsp) | 1 fl oz — max single liquid dose |
Cooking: Common Recipe Amounts
| Recipe says (ml) | US Spoons | Common ingredient |
|---|---|---|
| 1 ml | ⅕ tsp | Food coloring drops |
| 2 ml | ⅖ tsp | Vanilla extract (small) |
| 5 ml | 1 tsp | Vanilla, baking powder, spices |
| 7 ml | 1½ tsp | Yeast (dry active, 1 packet = 7g) |
| 10 ml | 2 tsp | Oil for greasing / extracts |
| 15 ml | 1 tbsp | Olive oil, butter, vinegar |
| 30 ml | 2 tbsp | Soy sauce, lemon juice, wine |
| 45 ml | 3 tbsp | Larger sauce amounts |
| 60 ml | ¼ cup | Milk additions, small liquid amounts |
UK vs US Teaspoon
The US teaspoon (4.929 ml) and the UK teaspoon (5.919 ml) are different — the UK teaspoon is about 20% larger. For most recipes this difference is negligible, but it matters for baking powder, salt, and spices where precision affects the result. When using a British recipe, a UK "1 tsp" = about 1.2 US teaspoons.
Convert Any Volume Instantly
For any volume conversion use the ConvertProf Volume Converter. Handles teaspoons, tablespoons, milliliters, cups, fluid ounces and more — exact factors, works offline.