Coffee Calculators
Cold Brew Dilution Calculator
https://www.coffeesizing.com/calculators/cold-brew-dilution/
Estimate only — not a cupping score, a water lab or a roast profile. Confirm on a test brew.
Cold Brew Dilution Calculator
Concentrate is a strong brew ratio sitting in the fridge; the drink is a milder ratio in the glass. If you steeped 1:8 and you want to drink 1:16, you add an equal mass of water (or milk). Weigh the concentrate, do not eyeball a ‘splash’.
Inputs
Results
- Water to add
- 200.0g
- Final drink
- 400.0g
The Result is indicative and educational. It does not constitute a design, a technical opinion or medical advice and does not replace calculations or verification by a person with the appropriate qualifications and authorisations. Before purchase, installation or use in practice – in particular in electrical installations – the Result should be verified by a qualified specialist. Details: Terms of Service, point 4.
Example products
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0.1 g coffee scale
Dilution is a ratio of masses. A scale beats ‘half concentrate, half water’ when the steep was 1:7, not 1:8.
Typical range: $20–$80
Airtight coffee canister
Concentrate picks up fridge smells. A sealed jar keeps the batch drinkable past day two.
Typical range: $20–$50
AeroPress
A compact way to press a small concentrate without a 2 L toddy bucket. Filter, then dilute with this math.
Typical range: $30–$50
Calculation method
The drink is milder than the concentrate by the ratio of the two brew ratios. Water to add is concentrate mass times (drinkRatio / concentrateRatio − 1). At 200 g of 1:8 going to 1:16 that is 200 g of water and 400 g in the glass. If drink ratio is not larger than concentrate ratio, there is nothing to dilute.
Exact formula
scale = drinkRatio / concentrateRatio. waterToAddG = concentrateG × (scale − 1), floored at 0 if drinkRatio ≤ concentrateRatio. finalDrinkG = concentrateG + waterToAddG. Limits: assumes strength falls in proportion to the ratio, as if both ratios extracted the same share of the coffee; ice melt and milk solids are omitted; ratios are mass:mass and concentrateG is the filtered liquid.
Concentrate is not espresso
A 1:8 cold brew is still a long extraction, not a 1:2 shot. Do not expect crema, and do not dial it with espresso TDS targets.
Frequently asked questions
Can I dilute with milk?
Use the water-to-add mass as milk mass if you want the same strength. Dairy adds solids, so the cup will taste richer than water at the same ratio.
What if I steeped by volume?
Convert to grams next batch. A cup of ground coffee weighs roughly 80–95 g and a cup of water about 240 g, so 1:8 by volume is nearer 1:20 by mass. This page assumes you weighed coffee and water at steep.
Ice in the glass?
Ice is extra water as it melts. Either serve on ice and drink fast, or use the flash-brew tool when ice is a planned part of the recipe.
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