Coffee-to-water
ratio calculator.

What does a 1:16 coffee ratio mean?

For every gram of dry coffee, use 16 grams of brewing water. The same relationship works at different scales: 20 g of coffee takes 320 g of water; 40 g takes 640 g. It tells you the quantities, not the grind setting, water temperature or brewing time.

The calculator keeps the relationship fixed when you change your batch. Check that the new batch fits your equipment. A larger brew may need a different pouring approach or timing; arithmetic alone cannot preserve the extraction.

A quick coffee-to-water chart

Which ratio should I use?

If you already enjoy a recipe, scale that recipe first. Otherwise, the 1:16 default sits within Counter Culture’s published 1:15–1:18 filter-coffee range. Moving from 1:16 to 1:15 uses more grounds for the same water. Moving to 1:18 uses less. Taste also depends on how much the water extracts.

Keep notes on the coffee, grind, quantities and method so you can repeat a result. Changing all of them at once makes it harder to know which adjustment helped.

Grams, cups and finished coffee

A cup on a coffee maker may not equal a US measuring cup. This tool explicitly uses 236.588 ml for a US cup and 29.574 ml for a US fluid ounce. For this household calculation, 1 ml of water is approximated as 1 g. Measure the water when the markings on a brewer are ambiguous.

Dry coffee is weighed in grams. We do not convert tablespoons into exact coffee weights because roast, grind and how you fill the spoon change the result.

Does this work for espresso or concentrate?

Espresso ratios commonly compare dry dose with the weight of espresso in the cup. That is an output measurement, so it should not be read as this calculator’s water input. A cold-brew concentrate also has a second ratio when you add water or milk after brewing. Use the dilution calculator for that step.