Coffee to water ratio calculator.
Enter any two of dose, water and ratio. The third is calculated. Pick a method and the ratio it actually wants is filled in for you.
Ratios by method
These are the bands each method sits in, not laws. Everything here is brew ratio — coffee to total brew water, before any is lost to the bed.
| Method | Typical ratio | Notes |
|---|---|---|
| Espresso | 1:2 – 1:2.5 | Ratio of dose to liquid in the cup, not to water through the machine |
| Moka pot | 1:7 – 1:10 | Effectively fixed by the basket and boiler volume |
| AeroPress | 1:12 – 1:16 | Wide by design; concentrate-and-dilute recipes go far tighter |
| V60 / pour-over | 1:15 – 1:17 | 1:16.6 is the common starting point |
| Kalita Wave | 1:15 – 1:17 | Flat bed, so it tolerates the tighter end better than a V60 |
| Chemex | 1:15 – 1:17 | Thick filter absorbs more — expect less in the cup than the maths says |
| Batch drip | 1:16 – 1:18 | Scale it and the ratio holds; the timing does not |
| French press | 1:12 – 1:15 | Full immersion, so the whole dose stays in contact throughout |
| Cold brew concentrate | 1:4 – 1:8 | Diluted to taste afterwards, usually around 1:1 with water or milk |
Grams, not millilitres
Water is weighed, not measured by volume. One millilitre of water weighs one gram closely enough that the two are interchangeable in a brewing context, so a scale replaces a jug and removes an entire class of error. If a recipe gives you millilitres, weigh that number of grams and move on.
Ratio is strength. Grind is extraction.
This is the distinction that makes the calculator useful rather than decorative. Ratio controls how much coffee ends up dissolved in the cup — how strong it tastes. Grind controls how much of the available material comes out of the grounds — whether it tastes sour, balanced or bitter.
So if a brew is sour or harsh, the ratio is not your problem; go to the dial-in guide and move the grind. If the flavours are clean and the cup is simply too weak or too intense, leave the grind alone and change the ratio here. Confusing the two is the single most common reason people chase the same coffee in circles.
Brew ratio and what actually reaches the cup
A V60 does not give you back all the water you pour. The bed and the paper hold roughly two grams for every gram of dry coffee, so 15 g of coffee and 250 g of water yields around 220 g of drink rather than 250 g. That is normal and it is already accounted for in the ratio bands above. It matters only if you are measuring beverage weight for an extraction yield figure, where the number you need is what came out, not what went in.
Coffee Aeye scales any recipe to the dose you actually have, keeps the ratio locked while it does, and logs what you brewed against how you rated it — so the ratio you keep coming back to becomes visible instead of remembered. Get it on Google Play — €4.29, one-time.