What 1:16 means
A ratio of 1:16 means sixteen parts water to one part coffee by weight. For 20 grams of coffee, multiply 20 by 16 to get 320 grams of brewing water. In reverse, divide the water amount by 16: 480 grams of water then needs 30 grams of coffee. The calculation applies to this ratio; the recipe must specify whether it uses brewing water or finished drink.
This simple calculation takes out the guesswork. But it does not yet tell you whether the coffee will taste balanced. Grind, temperature and process also determine what moves from the grounds into the cup.
Filter and espresso use different calculations
In filter recipes, the ratio often means dry coffee to water poured in. For espresso, it usually means dry coffee to finished drink. 18 grams in the basket and 36 grams in the cup is 1:2. This does not mean that only 36 grams of water were used in the machine; some remains in the puck and system.
For each recipe, therefore, state explicitly which quantities are meant. The word yield is also used for different things in everyday language. Drink yield in grams is the clearer term for an espresso recipe.
Small worked examples
For filter coffee at 1:15, you need 20 grams of coffee for 300 grams of water. At 1:17, you need around 17.6 grams. A higher second number means more water per gram of coffee. With an otherwise comparable result, the cup will often be less concentrated; however, the actual extraction can also change.
For espresso, 18 grams of coffee and 45 grams of drink give a ratio of 1:2.5. Adding 45 grams of water after extraction would be a different process from extracting a 90-gram drink through the same puck.
How to use the calculation in practice
- First choose a portion size suited to the method and the equipment's capacity.
- Establish whether your ratio uses brewing water or beverage yield.
- Calculate the missing variable and weigh both quantities.
- Record any extra water or ice separately so later dilution remains traceable.
Not every ratio fits every device
A calculation can be mathematically correct yet unsuitable in practice. An espresso basket that is too small will not hold your desired dose. A moka pot has fill levels specified by its design. And a large filter batch forms a different bed from a single cup. Equipment specifications therefore take priority over unrestricted scaling.
Check strength deliberately
If a coffee tastes good but too intense, first try adding a little water to the finished cup. If it becomes more pleasant, concentration was probably your main concern. Only then decide whether to change your brew ratio. This avoids unnecessarily losing a good extraction process.
The best number is the one that gives you coffee you enjoy and can reliably repeat. A ratio is an address for your recipe, not a ranking of flavour.