Cold Brew Ratio Calculator

Formula

Water mass = coffee mass × water-to-coffee mass ratio; water milliliters are approximately equal to grams near room temperature.

Worked example

With Ground coffee mass: 100 g, Water-to-coffee mass ratio: 8 g/g, water mass to add is 800 g.

Inputs and calculation

A ratio of eight means eight grams of water for each gram of ground coffee. Multiply the ground-coffee mass by that chosen ratio before adding water. The displayed relationship is Water mass = coffee mass × water-to-coffee mass ratio; water milliliters are approximately equal to grams near room temperature. Keep the fields' displayed units attached when reproducing this relationship by hand.

Worked numerical example

For example, enter ground coffee mass 100 g, water-to-coffee mass ratio 8 g/g. Those inputs produce water mass to add of 800 g. The same values also give approximate water volume 800 mL.

Holding the other example values fixed, change ground coffee mass from 100 to 110 g. The main output becomes 880 g. This comparison isolates the effect of that one input.

How to read and use the result

The output is mixing water, not the final cold-brew yield. Grounds retain water after steeping and filtering, so beverage volume is smaller than water poured in. Scale a chosen cold-brew recipe while preserving its water-to-coffee proportion.

Practical context

One hundred grams of grounds at an eight-to-one water-to-coffee mass ratio calls for 800 grams of water, roughly 800 milliliters. After steeping, grounds absorb some water, so a jug will deliver less than 800 milliliters of filtered concentrate. A concentrate recipe may be deliberately stronger than ready-to-drink coffee and later diluted.

Assumptions and scope

The ratio is by mass, and water density is approximated as one gram per milliliter. Coffee grind, roast, steeping time and concentrate dilution are independent choices. Replace the example defaults with measured inputs for your situation and account separately for factors outside these fields.

Checks and common mistakes

Do not interpret 1:8 as eight parts brewed coffee to one part grounds. Use a scale for repeatability; a scoop changes mass with grind and packing.

Common questions

What should I verify before using the Cold Brew Ratio Calculator result?

The calculator preserves the input ratio but cannot choose grind size, contact time or the final dilution that produces a preferred flavor. A coffee shop using 1:8 concentrate can scale a batch from 100 to 500 grams of grounds by multiplying the water from 800 to 4,000 grams. Whether that fits the brewing vessel depends on the combined slurry volume, which is outside the ratio equation.