Coffee-to-Water Ratio Calculator
Give any two values — coffee dose, water, or ratio — and solve for the third. Use the presets to jump straight to a common brew method.
Solved brew ratio
Why the ratio matters
Every brew method boils down to two numbers: how much dry coffee you use, and how much water passes through or steeps with it. Their relationship — the brew ratio, written 1:R — is the single biggest lever on strength. A tighter ratio like 1:12 packs more coffee into the same water and tastes bolder; a looser ratio like 1:18 stretches the same dose further and tastes lighter.
Ratio and extraction are often confused but they answer different questions. Ratio asks “how concentrated is this cup?” while extraction asks “how much of the coffee’s soluble flavor actually made it into the water?” You can brew a strong cup that is under-extracted (sour, thin flavor despite the strength) or a weak cup that is over-extracted (bitter despite being dilute). Getting the ratio right is the starting point; grind size and contact time do the rest.
Frequently Asked Questions
What does a 1:16 ratio mean?
It means 16 grams of water for every 1 gram of dry coffee. A 20g dose at 1:16 needs 320g (about 320ml) of water. The first number is always the coffee; the second is the water.
What ratio should I use for my brew method?
As a starting point: espresso runs about 1:2, moka pot around 1:10, French press around 1:15, pour-over methods like V60 or Kalita around 1:16, auto-drip machines around 1:17, and cold brew concentrate around 1:8 (before diluting to taste). These are starting points, not rules — adjust to your taste and your beans.
Should I measure water in grams or millilitres?
Either works for this calculator, since 1 gram of water is essentially 1 millilitre. Weighing on a scale is more accurate than reading a jug, because it accounts for water absorbed by the grounds and any splashing during the pour.
Why do stronger and weaker coffee use the same ratio idea?
The ratio controls strength directly — a lower number (like 1:12) makes a stronger, more concentrated cup, while a higher number (like 1:18) makes a lighter one. Extraction (how much flavor is pulled from the grounds) is a separate variable, controlled mostly by grind size and contact time.
General brewing guidance only, not a substitute for tasting and adjusting to your own beans, grinder, and water.