LEARN · COFFEE FUNDAMENTALS

Coffee-to-Water Ratio Explained: A Practical Guide

Coffee-to-water ratio is one of the simplest ways to make a brew recipe repeatable. It describes how much water you use for a given amount of ground coffee, so you can scale a recipe up or down without guessing.

Ratio is a starting point, not a universal rule. Grind size, contact time, water, brewer and the coffee itself still shape what you taste.

What is coffee-to-water ratio?

A ratio such as 1:16 means one part coffee to sixteen parts water by weight. If you use 20 g of coffee, multiply 20 by 16 to get 320 g of water.

How to read 1:15, 1:16 and 1:17

• 1:15 — 20 g coffee + 300 g water
• 1:16 — 20 g coffee + 320 g water
• 1:17 — 20 g coffee + 340 g water

These are examples for understanding the math, not fixed recipes that every coffee must follow.

A simple calculation

Choose the amount of coffee, then multiply it by the water side of the ratio. At 1:16, 30 g of coffee calls for 480 g of water. To scale the batch, keep the ratio and change both quantities proportionally.

Why ratio changes strength

Using more coffee for the same amount of water generally produces a more concentrated beverage; using more water for the same dose generally produces a less concentrated one. But strength is only part of what you perceive in the cup.

Ratio is not the same as extraction

Brew ratio, beverage strength and extraction are related, but they are not the same measurement. Changing the ratio changes the recipe, while grind size and contact time can change how much soluble material is extracted from the coffee. That is why two brews using the same ratio can still taste different.

How to adjust your recipe

Start with a repeatable ratio, taste the result, then change one variable at a time. If you change ratio, grind and brew time together, it becomes difficult to know which adjustment improved the cup.

Practical starting points

Instead of searching for one perfect number, use ratio to create a consistent baseline. From there, adjust for the coffee, brewer and the cup you want. A scale makes this easier because grams let you reproduce both the coffee dose and water amount precisely.

Keep the ratio, change the batch size

Once you understand the calculation, scaling becomes straightforward. The ratio gives your recipe structure; tasting tells you where to go next.