ML to Oz: The Liquid Conversion for Recipes

Your child's medicine says 5 mL. The measuring cup shows ounces. Your cocktail recipe says 2 oz. Your flight allows 100 mL liquids. Three contexts, one conversion — but getting it wrong on medicine is dangerous.

The Formula

1 US fluid ounce = 29.5735 mL

1 UK (imperial) fluid ounce = 28.4131 mL

The US and UK fluid ounce differ by 4% — enough to matter for medication.

| mL | US fl oz | UK fl oz | |-----|---------|---------| | 5 mL | 0.17 oz | 0.18 oz | | 10 mL | 0.34 oz | 0.35 oz | | 30 mL | 1.01 oz | 1.06 oz | | 50 mL | 1.69 oz | 1.76 oz | | 100 mL | 3.38 oz | 3.52 oz | | 240 mL | 8.12 oz | 8.45 oz | | 500 mL | 16.91 oz | 17.60 oz | | 1000 mL (1L) | 33.81 oz | 35.20 oz |

The Trench Truth: For cooking, the 4% US/UK difference doesn't matter. For medication, it can. A 5 mL dose measured as "0.17 oz" (US) vs "0.18 oz" (UK) is a 0.3 mL difference — negligible. But a 100 mL dose measured as "3.38 oz" (US) vs "3.52 oz" (UK) is a 4 mL difference — which matters for potent drugs. Always use mL for medication, never ounces. Syringes and medicine cups in India use mL for this reason.

📊 Medicine Dosing Table

| Common Dose | mL | US fl oz | Teaspoon Equivalent | |------------|-----|---------|-------------------| | Children's dose | 5 mL | 0.17 oz | 1 teaspoon | | Adult dose | 10 mL | 0.34 oz | 2 teaspoons | | Large dose | 15 mL | 0.51 oz | 1 tablespoon | | Cough syrup (max) | 30 mL | 1.01 oz | 2 tablespoons |

Travel Liquid Limits (TSA/BCAS)

| Rule | Limit | In fl oz | |------|-------|---------| | Carry-on liquid per container | 100 mL | 3.4 oz | | Total liquids in bag | 1000 mL | 33.8 oz | | Duty-free liquid | No limit* | — |

*Must be in tamper-evident bag with receipt

Cocktail Measurements

| Drink | oz | mL | Indian Bar Term | |-------|-----|-----|----------------| | Shot | 1.5 oz | 44 mL | "60 mL peg" (India uses 60mL) | | Jigger | 2 oz | 59 mL | "Large peg" | | Splash | 0.5 oz | 15 mL | "Chota peg" | | Dash | 0.1 oz | 3 mL | "Dash" |

Indian bars use 30 mL (small peg) and 60 mL (large peg) — not ounces.

Convert any volume with our Volume Converter.

Key Takeaways

1 US fl oz = 29.57 mL — UK fl oz is 28.41 mL (4% less)
Always use mL for medication — the 4% US/UK gap can affect dosing
TSA/BCAS limit: 100 mL per container — = 3.4 US fl oz
Indian bars use 30/60 mL pegs — not ounces
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Frequently Asked Questions

Why are US and UK fluid ounces different? The US fluid ounce (29.57 mL) is based on the US gallon (3.785 L ÷ 128). The UK/imperial fluid ounce (28.41 mL) is based on the imperial gallon (4.546 L ÷ 160). The 4% difference matters for medication but not cooking.

Should I use mL or ounces for medicine? Always mL. Medicine dosing in India uses the metric system. Syringes and dosing cups are marked in mL. The 4% US/UK difference can affect potent drugs — mL eliminates this ambiguity entirely.

How many mL is a standard Indian peg? Small peg: 30 mL (≈1 US fl oz). Large peg: 60 mL (≈2 US fl oz). Indian bars use mL, not ounces. A "shot" in the US is typically 44 mL (1.5 US fl oz).

What's the TSA liquid limit in mL? 100 mL per container, fitting in a single quart-size clear bag. Total limit: 1000 mL. In US fl oz: 3.4 oz per container. BCAS (India) follows the same 100 mL rule.

Is 1 cup the same as 8 fluid ounces? In the US, yes — 1 cup = 8 US fl oz = 236.6 mL. But a metric cup is 250 mL. An Indian "cup" varies by household. For baking, always specify which cup system you're using.

Sources: US FDA Medication Dosing Guidelines, TSA Liquid Rules, BCAS India Carry-On Rules, IBA Cocktail Standards.

ML to Oz: The Liquid Conversion for Recipes, Medicine, and Travel