Cold Brew Ratio Calculator
Cold brew is easier to get right by weight than by eyeball. Set the coffee and the concentrate ratio, then see the water to add and the finished volume after you dilute.
| Coffee | Water | Concentrate | Ready to drink |
|---|---|---|---|
| 50 g | 200 g | ~170 ml | ~340 ml |
| 100 g | 400 g | ~340 ml | ~680 ml |
| 150 g | 600 g | ~510 ml | ~1020 ml |
| 200 g | 800 g | ~680 ml | ~1360 ml |
Concentrate or ready to drink
A concentrate brews strong so it takes less fridge space and keeps longer once diluted. Ready to drink cold brew is simpler because you pour it straight, but it goes through the batch faster. Pick the style that matches how quickly your household drinks it.
Grind, time, and temperature
Use a coarse grind, close to what you would use for a French press, so the filter does not clog. Steep in the fridge for 12 to 18 hours, then strain. Cold water extracts slowly and gently, which is why cold brew tastes smoother and less acidic than hot brewed coffee.
Diluting to taste
Start with a 1:1 dilution and adjust. A 1:2 or 1:3 pour is lighter and closer to iced coffee. Milk counts as dilution too, so a splash of milk with a 1:1 concentrate lands near a 1:3 cup. Keep a note of what you liked so you can repeat it.
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Questions about this calculator
What is the best cold brew ratio?
For a concentrate, use 1 part coffee to 4 or 5 parts water by weight. For ready to drink cold brew, use 1:8. Dilute the concentrate 1:1 to 1:3 before serving depending on how strong you like it.
How long should cold brew steep?
Twelve to eighteen hours in the fridge is the sweet spot for most coarse grinds. Shorter tastes lighter and longer tastes stronger, but steeping past about 20 hours can turn bitter and woody.
Do you dilute cold brew concentrate?
Yes. A 1:4 or 1:5 concentrate is much stronger than brewed coffee, so add an equal part water or milk, or up to two or three parts for a lighter cup. Taste as you go.
How much cold brew does 100 g of coffee make?
At a 1:4 concentrate ratio, 100 g of coffee steeps in 400 g of water and yields roughly 340 ml of concentrate. Diluted 1:1, that becomes about 680 ml, or close to three cups.
What grind size for cold brew?
Coarse, similar to French press. Fine grounds clog the filter and can make the brew muddy. If your grinder has a cold brew setting, start there and adjust.
How long does cold brew last in the fridge?
Strained concentrate keeps about a week in a sealed container. Ready to drink cold brew is best within three to four days. Glass and a tight lid help it stay fresh.
Can I make cold brew hot and chill it?
You can, but it will taste different. Hot brewing pulls more acidity and oils, so a chilled hot brew is closer to iced coffee than true cold brew. The long cold steep is what gives cold brew its smooth, low acid profile.