Interactive tool · 計算
Cold Brew Ratio Calculator
Tell it how much cold brew you want and how strong. It tells you exactly how much coffee and water to use — by weight, the only way that's repeatable.
How the math works
Cold brew ratios are expressed by weight — 1:5 means 1 gram of coffee for every 5 grams (= 5 ml) of water. Volume scoops lie: a "cup of grounds" can vary by 30 grams depending on grind and roast. A $15 kitchen scale ends the guessing forever.
The calculator also corrects for the cold brew tax nobody mentions: grounds absorb roughly twice their weight in water. Brew with exactly the water your target volume needs and you'll come up short, so we add the absorbed water back into the water figure for you.
Which ratio should you pick?
- 1:4 to 1:5 — concentrate. The flexible choice. Cut it 1:1 with water or milk over ice, and one batch serves black-coffee drinkers and latte people alike. 1:5 is the ratio we brew every control batch with.
- 1:8 — ready to drink. Straight from the fridge to the glass, no dilution. Closest to what a café hands you.
- 1:10 and up — light. Tea-like body. Some single origins shine here; most grocery beans get watery.
Want the full reasoning, steep-time tests, and grind advice? Start with the brewing guides.