Last updated: 2026-06-16

The Coffee-to-Water Ratio

The brew ratio describes how much coffee to use for a given amount of water. It is written as 1 : N, where N is the grams of water poured over each gram of ground coffee. A 1:16 ratio means 16 grams of water for every gram of coffee. Because water weighs close to 1 gram per millilitre, the water figure also stands in for millilitres on most kitchen scales.

The Golden Ratio

The Specialty Coffee Association recommends about 55 grams of coffee per litre of water, which falls between 1:15 and 1:17. This band is often called the golden ratio because it balances extraction and strength for filter brewing. The coffee mass follows directly from the ratio:

where $C$ is the coffee mass, $W$ is the water mass, and $N$ is the ratio denominator.

Worked Example

For 425 grams of water at a 1:16 ratio:

At roughly 5.3 grams per level tablespoon of medium grind, that is close to 5 tablespoons.

Ratios by Brew Method

The ideal ratio shifts with the method and the desired intensity:

A lower denominator yields a stronger cup; a higher one a lighter one. Weighing both coffee and water gives the most repeatable result, since grind size and roast make volume measures vary from one scoop to the next.