One standard US cup holds 240 ml. So to find 2/3 of that, you just do the math: 240 divided by 3 equals 80, then multiply by 2. That gives you 160 ml.
Yes, you heard that right: 2/3 cup = 160 ml. No more guessing, no more ruined batter. You can literally tell your friends, “I know the secret of the 160 ml.” They’ll be impressed—or at least mildly amused.
Side note: If you’re using a metric cup (like in Australia or the UK), it’s often 250 ml, which makes 2/3 equal to about 167 ml. So, check your cup’s origin story before you pour. It matters, I promise.
Why does this matter for your brownies (or your sanity)?
Baking is a science, but let’s be honest: it’s also a chaotic, delicious experiment. Getting 2/3 wrong can turn your cookies into pancakes. Not that pancakes are bad, but they’re not cookies.
I once used 1/2 cup instead of 2/3 in a bread recipe. The loaf came out so flat, it looked like a tortilla. A sad, dense tortilla that cried gluten tears. Don’t be that person.
