A recipe says “1.5 cups of water” and your only measuring tool is a jug marked in ml. Now what? You multiply, that’s what, and this tool does it the instant you type. The hitch is that “a cup” isn’t a single agreed size, so the right answer depends on where the recipe came from.
Most recipes you’ll meet online assume the American measure. One US cup is 236.588 ml. So 1.5 cups is about 354.9 ml, two cups is 473.2 ml, and a single half cup lands at 118.3 ml. Clean math, no formula, just a fixed multiplier running as fast as you can enter numbers.
The cup problem nobody mentions on the recipe card
Here’s the part that quietly ruins bakes. There’s more than one cup standard in circulation:
- US cup: 236.588 ml. What American recipes and the big recipe sites default to.
- Metric cup: 250 ml. Standard across Australia, New Zealand, and plenty of countries that adopted metric cleanly. It’s what’s printed on a lot of European measuring cups too.
- Old UK cup: roughly 284 ml. Imperial-era, lurking only in vintage British cookbooks.
The spread between a US cup and a metric cup is about 5.6%. Pour one cup of stock for a soup and nobody on earth will taste the difference. Stack that 5.6% across four cups of flour in a cake, though, and the ratio shifts enough to change how it rises. The converter lets you pick which cup you mean, so a recipe written for one standard translates straight into the other.
Numbers you’ll reach for constantly
A handful of these come up in basically every kitchen session:
| Cups (US) | Milliliters |
|---|---|
| 1/4 | 59.1 |
| 1/3 | 78.9 |
| 1/2 | 118.3 |
| 2/3 | 157.7 |
| 3/4 | 177.4 |
| 1 | 236.6 |
| 2 | 473.2 |
The full reference table in the tool covers these and more. For standard fractions you can read the answer straight off without typing a thing.
How to use it
Type a cup value and the milliliter result appears on the spot, no submit button. Use the toggle to switch between US and metric cups so you’re matching whatever the recipe assumes. It’s a fixed-factor calc that runs in the page itself with the exact 236.588 number baked in, which means nothing you enter gets uploaded and it stays usable offline once the page has loaded.
One honest limit worth stating: this converts volume to volume only. It can’t tell you what one cup of flour weighs in grams, because that hinges on the ingredient’s density, and packed brown sugar weighs very differently from sifted flour. For dry baking precision, a kitchen scale beats any cup. But when a recipe hands you cups and your gear only speaks milliliters, this is the conversion you want.
Common questions
How many ml is 1 cup?
236.588 ml for a US cup, which is what most recipes mean. A metric cup is 250 ml, and the old UK imperial cup was about 284 ml. The tool uses the exact figures, not rounded ones.
Is a cup 250 ml or 240 ml?
Neither, strictly. A US cup is 236.588 ml. The 250 ml figure is the metric cup used in Australia and elsewhere, and 240 is just a common rounding of the US cup you’ll see on some labels.
Why doesn’t 1 cup equal exactly 250 ml?
Because the US cup descends from an 8 fluid ounce measure, which works out to 236.588 ml, not a round 250. Metric countries defined a tidy 250 ml cup separately, and the two were never merged.
Can I use this to convert cups of flour to ml?
Yep, a US cup is 236.588 ml whether it holds flour or water, since that’s a volume. But converting cups to grams for dry goods needs the ingredient’s density, which this volume tool doesn’t handle. Weigh dry ingredients for accuracy.
Does anything get sent to a server?
Nope. It’s plain browser arithmetic with a fixed factor, so your values stay on your device and it runs offline after the page loads.