Last Updated: December 2025
Master the art of cold brew concentration with our simple ratio calculator. Whether you’re aiming for a strong concentrate or a ready-to-drink coffee, input any two variables—Coffee Mass, Water Mass, or desired Ratio—to instantly find the third.
Cold Brew Ratio Calculator
Cold Brew Ratio Formula
The cold brew ratio is a simple linear relationship between the mass of water and the mass of coffee used. It is typically expressed as X:1, where X is the amount of water per 1 unit of coffee.
Formula Sources: Counter Culture Coffee, Blue Bottle Coffee
Variables Explained
- Coffee Mass (Grams): The weight of the dry, ground coffee used for brewing. This is the denominator in the ratio.
- Water Mass (Grams or mL): The volume of water used. Since water density is approximately 1 g/mL, mass and volume are interchangeable in this context.
- Desired Water-to-Coffee Ratio (X:1): The intensity level. Common ratios range from 5:1 (very concentrated) to 15:1 (ready-to-drink).
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- Dilution Ratio Calculator
- Grind Size Conversion Tool
What is the Cold Brew Ratio?
The cold brew ratio is the single most important factor determining the strength and flavor profile of your final cold brew concentrate. Unlike hot coffee brewing, which relies heavily on time and temperature, cold brewing uses a long steep time, making the ratio critical for extraction. A tighter ratio (e.g., 1:5) produces a very strong concentrate, while a wider ratio (e.g., 1:15) results in a weaker, ready-to-drink coffee.
Understanding this ratio is key to batch brewing. By calculating the exact amount of coffee and water needed, you ensure consistency, whether you’re making a single cup or a large commercial batch. The ratio you choose will also dictate how much water or milk you need to add to the concentrate later to achieve your preferred drinking strength.
How to Calculate Cold Brew Ratio (Example)
Let’s find the required Water Mass for a 10:1 ratio using 250 grams of coffee.
- Identify Knowns: Coffee Mass (C) = 250g, Desired Ratio (R) = 10.
- Identify Unknown: Water Mass (W).
- Select Formula: Since Ratio = Water / Coffee, we rearrange to find Water: $\text{Water Mass} = \text{Ratio} \times \text{Coffee Mass}$.
- Substitute Values: $\text{Water Mass} = 10 \times 250\text{g}$.
- Calculate Result: $\text{Water Mass} = 2500\text{g}$ (or 2500 mL).
Frequently Asked Questions (FAQ)
- What is a standard cold brew ratio?
- A common ratio for a strong concentrate is 1:8 (1 part coffee to 8 parts water). Ratios between 1:5 and 1:10 are usually considered concentrate, while 1:12 to 1:16 are ready-to-drink.
- Why do I need to measure coffee and water by mass?
- Mass (grams) is a more accurate and consistent measurement than volume (cups/spoons) for coffee grounds. Using mass ensures that you always have the same amount of coffee solids, regardless of how fine the grind is or how tightly it is packed.
- What if I input all three values?
- The calculator will check if the three values are mathematically consistent. If they are, it will confirm the ratio. If they are inconsistent, it will show an error, prompting you to adjust your inputs.
- Is the ratio the same for hot and cold brew?
- No. Hot coffee typically uses a much wider ratio (e.g., 1:15 to 1:17) because the high temperature extracts flavor quickly. Cold brew uses a tighter ratio (more coffee) to compensate for the lower extraction efficiency of cold water.