Cups to Milliliters Conversion
1 US cup = 236.6 ml
1 US cup equals 236.6 milliliters. Simple, right? Not quite.
The confusion starts with different cup standards. US recipes use the 236.6ml cup. Australian and UK recipes often use the 250ml metric cup. Japanese recipes use the 200ml cup. Canadian recipes might use either US or metric cups depending on when they were written.
This 5% difference between US and metric cups matters in baking. A cake recipe calling for 3 cups of milk means 710ml with US cups but 750ml with metric cups. Those extra 40ml can turn a perfect crumb into a soggy mess. Professional kitchens avoid this problem entirely by measuring liquids in milliliters or liters.
How to Convert
Multiply cups by 236.6 to get milliliters. For 2 cups: 2 x 236.6 = 473.2ml. Round to 475ml for practical use.
Worked example: Converting 1.5 cups of chicken stock. Calculate 1.5 x 236.6 = 354.9ml. Round to 355ml. Your measuring cup probably has ml markings on one side. Use those instead of the cup lines for accuracy.
For metric cup conversions, multiply by 250 instead. A recipe calling for 2 metric cups needs 500ml exactly. Check if the recipe specifies which cup standard it uses. American recipes rarely mention it because they assume US cups.
Common Mistakes
Using the wrong cup standard without checking. A British recipe for lemon curd might call for 1 cup of lemon juice. That means 250ml, not 237ml. The extra acidity affects the set.
Rounding too aggressively. Rounding 236.6ml to 240ml seems harmless. Do it four times in a recipe and you've added an extra 14ml. In bread dough, that changes hydration by 2-3%.
Measuring hot liquids in plastic measuring cups. They warp at temperatures above 140F. Use glass for anything hotter than warm tap water. Pyrex cups show both cup and ml markings clearly.
Pro Tips
Buy a 1-liter glass measuring cup with ml markings. Covers 90% of recipe needs. The angled OXO version lets you read measurements from above without crouching.
For recipes that list both cups and ml, trust the ml. The cup measurement is often rounded for convenience. '1 cup (250ml)' means the recipe developer used exactly 250ml.
When scaling recipes, work in milliliters. Doubling 1.5 cups gets messy (3 cups). Doubling 355ml is straightforward (710ml). Digital kitchen scales often measure ml too. Water and milk weigh 1g per ml, so 237ml = 237g on the scale.
Ingredient-Specific Notes
Water
236.6ml per US cup at room temperature. Weighs exactly 236.6g because water has a density of 1g/ml. Hot water expands slightly but the difference is negligible for cooking. Ice water contracts to about 235ml per cup.
Milk
236.6ml per cup, essentially identical to water for volume purposes. Whole milk weighs about 244g per cup due to fat content. The volume stays the same whether you use skim or heavy cream.
Oil
236.6ml per cup by volume, but only weighs about 215g because oil is less dense than water. This matters when substituting oil for butter by weight in baking. Olive oil and vegetable oil have nearly identical volumes.
Honey
236.6ml per cup, but weighs 339g due to high density. Flows slowly at room temperature. Warm the measuring cup with hot water first to make honey pour cleanly. One cup of honey equals about 1.4 cups of sugar by weight.
Heavy cream
236.6ml per cup. Whips to approximately 475ml (2 cups) when doubled in volume. Temperature matters: cream whips best at 38F. The fat content (36%) doesn't affect the volume measurement.
Frequently Asked Questions
How many ml in 1/4 cup?
59.15ml, which rounds to 60ml for practical use. Most liquid measuring cups show a 60ml line. For 1/3 cup: 78.9ml (round to 80ml). For 1/2 cup: 118.3ml (round to 120ml). For 2/3 cup: 157.7ml (round to 160ml). For 3/4 cup: 177.4ml (round to 175ml or 180ml). These slight roundings won't affect most recipes.
Is 250ml exactly 1 cup?
No. 250ml equals 1 metric cup, used in Australia, New Zealand, and Canada. 1 US cup equals 236.6ml. The 13.4ml difference (about 1 tablespoon) matters in baking but not in cooking. British recipes might use either, though newer ones tend toward metric. Japanese recipes use 200ml cups.
Why don't my measuring cups match the conversion?
Cheap measuring cups can be off by 5-10%. Test yours by filling with water and weighing: 1 cup should weigh 237g. Glass cups are generally more accurate than plastic. Nesting metal cups often run small because manufacturers leave room for stacking. Stick with one good glass measure for liquids.
Do I need to adjust ml measurements for altitude?
No for measuring. Yes for cooking results. Water boils at 202F at 5,000 feet instead of 212F at sea level. This affects cooking times, not volumes. Your 237ml of water is still 237ml. But pasta takes 2-3 minutes longer to cook, and candy thermometer readings need adjustment. Baking recipes may need 1-2 tablespoons extra liquid above 3,000 feet.
Which measuring method is most accurate?
Weight beats volume every time. But for liquids, milliliters are excellent. A graduated cylinder is most precise, then glass measuring cups, then plastic cups. Never use dry measuring cups for liquids. The meniscus (curved surface) makes it impossible to level accurately. For water-like liquids, remember that ml = grams, so a scale works perfectly.