What Is the Coffee to Water Ratio?
The coffee-to-water ratio is the relationship between the weight of ground coffee and the weight of brewing water. It is the single biggest factor in how strong and balanced your cup tastes. A ratio of 1:16 means 1 gram of coffee for every 16 grams (millilitres) of water — a popular "golden ratio" for filter coffee, while 1:15 brews a bolder cup and 1:18 a lighter one.
How to Use This Calculator
Choose whether you know your coffee dose or your water amount, type that figure in grams, and enter your preferred ratio (the "N" in 1:N). The calculator instantly returns the matching measurement so you can scale any recipe up or down with confidence. Because 1 ml of water weighs about 1 g, you can read the water value in millilitres too.
The Formula Explained
Two simple relationships drive every result:
\(\text{Coffee (g)} = \dfrac{\text{Water (g)}}{\text{Ratio}}\) and \(\text{Water (g)} = \text{Coffee (g)} \times \text{Ratio}\). Both come from the same proportion, just solved for a different variable.
$$\text{Coffee (g)} = \frac{\text{Water (g)}}{\text{Ratio}}$$$$\text{Water (g)} = \text{Coffee (g)} \times \text{Ratio}$$
Worked Example
Suppose you want to brew 320 g of water at a 1:16 ratio. Coffee = 20 g of ground coffee.
$$\text{Coffee} = \frac{320}{16} = 20\ \text{g}$$Going the other way, 20 g of coffee at 1:16 needs 320 g of water.
$$\text{Water} = 20 \times 16 = 320\ \text{g}$$FAQ
What ratio should I start with? 1:16 is a reliable starting point for pour-over and drip. Adjust by ±1 to taste.
Does this work for espresso? Espresso uses much tighter ratios, typically 1:2. Enter 2 as the ratio for an espresso "brew ratio".
Grams or millilitres? Water in grams and millilitres are practically equal, so use whichever your scale or jug shows.
