Cold Brew Ratio Calculator - Coffee, Water & Caffeine

A cold brew ratio is the proportion of coffee grounds to room-temperature water you steep for 12 to 24 hours to make a smooth, low-acid concentrate. The widely cited range is 1:5 to 1:5.6 by mass to volume, with 1:5 as the strong baseline most home baristas start from. This calculator uses the same math as commercial producers so you can size a small jar or one-liter batch with confidence.

• • Size a week of ready-to-drink concentrate: Pick the volume of finished concentrate you want on hand, then convert it to grams of coffee and milliliters of water.
• • Match a specific coffee bag: If you already own 250 g of coarse grounds, run the math backwards to find how much water pairs with it.
• • Compare brew strengths: Switch between 1:5 strong, 1:5.3 regular, and 1:5.6 light to see the coffee, water, and caffeine difference before committing.
• • Plan for a crowd without waste: Enter the cups your guests will drink and the calculator returns a precise shopping list of grounds plus the steeping window.

Cold brew is not just hot coffee that has cooled down. The long contact with room-temperature water pulls different oils and acids out of the grounds than a 30-second espresso does, which is why the result tastes smoother. Because the water never reaches brewing temperature, you need a higher coffee dose for a flavorful strength, and the ratio expresses that. Hot drip coffee typically uses 1:15 to 1:17 grams of coffee per milliliter of water, roughly three times weaker than cold brew concentrate before you dilute it.

Once your concentrate is dialed in, the Coffee Calculator covers the standard hot drip ratio so you can compare cold and hot recipes on the same scale.

The calculator applies the standard cold brew ratio to convert your finished concentrate volume into the exact grams of coffee and milliliters of water to combine.

• Target concentrate (mL): Volume of finished cold brew you plan to drink or store.
• Coffee-to-water ratio (mL/g): Mass-to-volume ratio. 5 is the strong baseline; 5.6 is light.
• Grounds absorption (%): Share of starting water the grounds retain. The default 20% leaves 80% as concentrate.
• Coffee bulk density (g/mL): Used to convert grams of grounds into tablespoons without a scale. Coarse grounds sit near 0.42 g/mL.

The math has two stages. First, it reverses the absorption loss so the starting water leaves exactly the concentrate volume you want. Second, it divides that water by your chosen ratio to give grams of coffee, then converts grams to tablespoons using the bulk density of coarse grounds for cooks without a scale. Caffeine is estimated at 2,787 mg per liter, the average for 1:5 batches, and labeled as an estimate because origin, roast, and steep time all shift the real number.

According to Omni Calculator Cold Brew Ratio, the recommended coffee-to-water ratio for cold brew is 1:5 by mass to volume and the concentrate retains about 80% of the starting water.

The same divide-by-retention math shows up in grain cooking, and the Rice to Water Ratio Calculator applies the equivalent logic to rice for stovetop or rice cooker batches.

Four ideas drive every cold brew recipe. Understanding them keeps the ratio from feeling like a magic number.

Once you internalize the ratio and the absorption term, cold brew becomes one repeating equation. The calculator automates that math so you do not have to do it while holding a bag of grounds.

When you want to convert coffee grams into tablespoons without a scale, the Grams to Tbsp Calculator uses ingredient density to give a reliable scoop estimate.

Plan a batch in four steps. The defaults work for most home brewing jars.

1. 1 Enter your target concentrate volume: Choose mL, cups, or liters and enter the volume of finished concentrate you want. A 1.5 L French press holds roughly 1,200 mL of concentrate after absorption losses.
2. 2 Pick a brew strength: Select Strong (1:5), Regular (1:5.3), or Light (1:5.6). Switch to Custom ratio for values outside the presets; valid custom ratios sit between 3 and 8 mL of water per gram of coffee.
3. 3 Adjust grounds absorption if needed: Leave 20% as the default unless your grind is unusually fine or coarse. Fine grounds can absorb up to 24%, extra-coarse grounds can drop to 17%.
4. 4 Weigh, steep, and strain: Weigh the coffee grams shown, combine with the required water in a sealed jar, steep at room temperature for the suggested hours, then filter through a paper strainer.

If you target 500 mL of concentrate at the standard 1:5 strong ratio, the calculator returns 625 mL of water and 125 g of coffee. Steep 13 hours, filter, and dilute each serving 1:1 with water or milk to keep daily caffeine intake predictable.

If you keep your recipe in cups but want to scale it for a 2 L jar, the Cooking Measurement Converter handles cups, tablespoons, ounces, and milliliters in one step.

Five practical reasons home brewers and small cafes reach for this tool instead of guessing.

• • Repeatable batches: Lock in a ratio and absorption factor, then make the same tasting concentrate every weekend.
• • Less wasted coffee: Size the batch to the jar you own, so you stop over-buying beans or pouring out half-empty concentrate bottles.
• • Predictable caffeine: Caffeine per liter is shown for each batch, which makes it easier to plan around personal tolerance.
• • Strength comparison: Switching between 1:5, 1:5.3, and 1:5.6 shows the difference in coffee dose, water, and caffeine before you change anything in the kitchen.
• • Works with cups, mL, and liters: Pick the unit that matches your jar's markings.

The biggest gain is removing guesswork from steeping time. The recommended hours window gives you a safe starting point to adjust from your palate.

After the calculator returns the caffeine per batch, the Coffee Kick Calculator maps that dose onto your sleep and alertness window so you can time your concentrate intake.

The ratio is the headline number, but five variables quietly change how the concentrate tastes.

• • The caffeine estimate uses the published 2,787 mg/L average for a 1:5 batch. Real caffeine varies by bean origin, roast level, and steep time, so treat it as a planning tool, not a measurement.
• • Absorption is modeled as a single percentage. Coarse grinds absorb closer to 17% while fine grinds can reach 24%, so the calculator clamps the absorption control to that realistic window.

These factors do not change the math, but they explain why two brewers on the same recipe end up with different cups. Once the ratio and steep time are dialed in, grind size and water quality are usually where taste drifts start.

According to National Coffee Association USA Cold Brew Guide, cold brew coffee is brewed with time rather than heat and produces a smoother, less acidic concentrate than drip coffee.

Because grind size shifts bulk density and therefore the grams-per-tablespoon conversion, the Ingredient Volume to Weight Converter is a useful companion when you need to translate between scoops and grams for cold brew recipes.