Coffee Brew Ratio Calculator

Specialty coffee talks in ratios — 1:16 means one gram of coffee for every sixteen grams of water — because that is the one number that transfers between kitchens. Volume does not: a scoop of light roast and a scoop of dark roast differ in mass by a noticeable margin, and a "cup" is 240 ml in one country and 150 in another. This tool carries method-specific defaults (pour-over 1:16, French press 1:15, AeroPress 1:14, espresso 1:2, cold brew 1:8) plus grind and time reminders, and recalculates whichever side you did not type, so you can plan from "I have 25 g of beans" or from "I want 400 ml".

The ratio sets strength; it does not set extraction. Those are two separate axes and confusing them is behind most disappointing cups. How much coffee you dose against how much water decides how concentrated the drink is. How finely you grind, how hot the water is and how long the two stay together decides what fraction of the available solubles actually leaves the grounds. A brew can be strong and under-extracted at once — sour, thin-tasting and heavy — and the fix there is a finer grind or a longer contact time, not more coffee.

Worth knowing that the defaults here are on the strong side of the published standard. The Specialty Coffee Association's golden cup target is about 55 grams of coffee per litre of water, which works out near 1:18; the 1:16 default is 62.5 g/L. Neither is wrong — the standard was set on a mid-century American palate and much of the current third-wave convention brews stronger — but if you are checking against a published guideline, that is the offset to keep in mind.

The arithmetic also cannot tell you what ends up in the cup. Wet grounds retain roughly twice their own weight in water, so 25 g of coffee brewed at 1:16 takes 400 g of water in and leaves about 350 g of beverage after the bed holds back its share. Plan a carafe volume from the water figure and you will come up short every time. Espresso is the exception that proves the point: its 1:2 is dose to liquid yield, measured on the way out, so no retention correction applies — the same notation means a different thing there.