Cold Brew Ratio Calculator Formula

Understand the math behind the cold brew ratio calculator. Each variable explained with a worked example.

Use the Cold Brew Ratio Calculator

Formulas Used

Coffee Needed

coffee_grams = round(desired_ml / brew_style)

Coffee (cups)

coffee_cups = round(desired_ml / brew_style) / 85

Water Needed

water_ml = desired_ml

Servings (diluted if concentrate)

servings = brew_style <= 6 ? floor(desired_ml / 120) : floor(desired_ml / 240)

Variables

VariableDescriptionDefault
desired_mlDesired Final Volume(mL)1000
brew_styleBrew Style6
steep_hoursSteeping Time(hours)18

How It Works

How to Calculate Cold Brew Ratio

Common Ratios (Coffee : Water by weight)

  • 1:6 - Concentrate. Dilute 1:1 with water, milk, or ice before serving. Bold, strong flavor.
  • 1:12 - Ready to drink. No dilution needed. Balanced strength.
  • 1:15 - Light and refreshing. Good for iced coffee on hot days.

    • Steeping

    Steep ground coffee in cold or room-temperature water for 12-24 hours. Most recipes recommend 16-18 hours. Longer steeping increases extraction but can also increase bitterness.

    Grind Size

    Use a coarse grind (similar to French press). Fine grinds will over-extract and make the cold brew harsh and gritty.

    Worked Example

    1 liter of cold brew concentrate (1:6 ratio), 18-hour steep.

    desired_ml = 1000brew_style = 6steep_hours = 18
    1. 01Coffee = 1000 / 6 = 167 g (about 2 cups)
    2. 02Water = 1000 mL
    3. 03Steep for 18 hours in the refrigerator
    4. 04Strain and dilute 1:1 for 8 servings of 240 mL each.

    Frequently Asked Questions

    Can I steep cold brew at room temperature?

    Yes. Room temperature extraction is faster and may produce a slightly different flavor profile than refrigerator steeping. Steep for 12-16 hours at room temperature, then strain and refrigerate. Both methods work well.

    How long does cold brew keep?

    Strained cold brew concentrate keeps for up to 2 weeks in the refrigerator. Ready-to-drink strength keeps for about 1 week. The flavor gradually becomes stale and flat over time.

    Is cold brew less acidic than hot coffee?

    Cold brew is generally about 60-70% as acidic as hot-brewed coffee because cold water extracts fewer acidic compounds. This makes it gentler on the stomach for many people.

    Ready to run the numbers?

    Open Cold Brew Ratio Calculator