A cold brew ratio calculator takes the guesswork out of cold brew coffee. Unlike hot brewing where temperature extracts flavors quickly, cold brew relies on time and the right coffee-to-water ratio to achieve smooth, low-acid coffee. This calculator gives you exact amounts for your desired batch size and concentration level.
Cold Brew Settings
Ready-to-drink strength. No dilution needed.
Amount of finished cold brew you want to make
Your Cold Brew Recipe
Set your batch size and click Calculate
How to Use the Cold Brew Ratio Calculator
Cold brew coffee is made by steeping coarsely ground coffee in cold water for 12-24 hours. The slow, cold extraction produces a smooth, low-acid concentrate that's noticeably less bitter than hot-brewed coffee. The right coffee-to-water ratio is the most important variable for consistent results.
Step 1: Choose Your Concentration Level
Cold brew can be made at different strengths. Concentrate (1:4 to 1:8) is meant to be diluted before drinking — usually 1:1 with water or milk. This gives you more flexibility and produces more servings per batch. Regular strength (1:8 to 1:12) is ready to drink over ice without dilution. The cold brew ratio calculator adjusts coffee and water amounts based on your choice.
Step 2: Enter Your Batch Size
Enter the amount of finished cold brew you want to produce, not the amount of water. For a 4-cup batch at 1:8 ratio, you'll need about 60g of coffee (roughly 8 tablespoons) in 4 cups of water. Cold brew keeps for 1-2 weeks in the refrigerator when sealed, so making a larger batch saves time.
Step 3: Grind and Steep
Grind coffee to medium-coarse (similar to rough sand). Finer grinds over-extract and make cold brew muddy and bitter. Add the ground coffee to your brewing vessel, pour cold filtered water over it, stir gently, cover, and steep. Room temperature steeping takes 12-16 hours; refrigerator steeping takes 18-24 hours. The calculator shows the recommended steep time for your grind size.
Step 4: Filter and Store
Strain the cold brew through a fine mesh strainer lined with cheesecloth, a nut milk bag, or a paper coffee filter. This step takes 10-30 minutes depending on your filter. Don't squeeze the coffee grounds — this introduces bitter compounds. Store the filtered cold brew in a sealed container in the refrigerator for up to 2 weeks.
FAQ
What is the best cold brew coffee ratio?
For concentrate (to be diluted before drinking): use a 1:4 to 1:8 ratio (coffee:water by weight). For ready-to-drink strength: use 1:8 to 1:15. The most popular home ratio is 1 cup coffee grounds to 4 cups water for concentrate, which you then dilute 1:1 with water or milk. Stronger ratios (1:4) extract more slowly and produce intense concentrate.
How long should I steep cold brew coffee?
Cold brew steeps 12-24 hours at room temperature or in the refrigerator. Room temp steeping is faster (12-16 hours) but can become over-extracted and bitter if left too long. Refrigerator steeping (18-24 hours) is more forgiving and produces a cleaner flavor. Coarse ground coffee generally steeps for the full 24 hours; medium-coarse for 16-20 hours.
What grind size should I use for cold brew?
Use coarse or medium-coarse ground coffee for cold brew. Fine grounds over-extract and make the cold brew bitter and muddy. Coarse grounds (similar to sea salt) produce the cleanest, smoothest cold brew. If using a French press for cold brew, use coarse grounds to make straining easier.
How do I dilute cold brew concentrate?
Start with a 1:1 ratio of concentrate to water or milk and adjust to taste. A typical serving is 2 oz concentrate in 6 oz water or milk over ice. You can also drink it straight over ice, which naturally dilutes it as the ice melts. The calculator shows serving suggestions based on your concentration level.
Can I make cold brew in the refrigerator vs room temperature?
Both work. Room temperature cold brew (65-75°F) steeps in 12-16 hours and has a slightly different flavor profile — often described as fuller-bodied. Refrigerator cold brew (35-40°F) takes 18-24 hours but is more forgiving (less risk of over-extraction or bacterial growth). Both methods produce excellent cold brew.
Is this cold brew calculator free?
Yes, the cold brew ratio calculator is completely free with no signup required. Enter your desired batch size and concentration level to get exact measurements.