Cold Brew Coffee Ratio Calculator
Measure coffee and water for cold brew at your chosen strength — concentrate or ready-to-drink — with the dilution worked out for you.
How it works
Coffee (g) = water (ml) ÷ ratio · Ratio is parts water to 1 part coffee by weight/volume
Cold brew extracts slowly in cold water over 12–18 hours, producing a smooth, low-acid coffee. Strength is set by the water-to-coffee ratio: a tight 4–8:1 makes a concentrate you dilute with water or milk to taste, while 10–15:1 brews something you can drink straight. Use a coarse grind and filter well, since fines make the brew cloudy and over-extracted.
Worked example
For 1,000 ml of water at an 8:1 ratio you need 1,000 ÷ 8 = 125 g of coarse-ground coffee. That yields a concentrate; diluting it 1:1 with water or milk gives about 2,000 ml of ready-to-drink cold brew.
Frequently asked questions
What ratio should I use for concentrate vs ready-to-drink?
A concentrate uses roughly 4–8 parts water to 1 part coffee and is diluted before serving. For coffee you can drink straight from the jar, brew weaker at about 10–15:1. This calculator gives the coffee weight for whichever ratio you pick.
How long should cold brew steep?
Twelve to eighteen hours is the usual window at room temperature or in the fridge. Shorter is weaker and brighter; much longer can turn bitter or woody. Filter promptly once it is done so extraction stops.
Why use a coarse grind?
Coarse grounds extract evenly over the long steep and are easy to filter out, giving a clean cup. Fine grounds over-extract, pass through filters as sediment, and make the brew muddy and harsh.
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This calculator is for educational purposes. Double-check important results before acting on them.