Coffee to Water Ratio Calculator

Find how much coffee or water you need for a given brew ratio, from a strong 1:15 to a mild 1:18. Enter one amount and get the other in grams. Calculates in your browser.

1 gram of water ≈ 1 ml, so grams and millilitres match for water.

Coffee needed

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Ratio used-
Brew summary-

Show the math

A 1:ratio brew uses that many grams of water for each gram of coffee:

coffee = water ÷ ratio  ·  water = coffee × ratio

A 1:16 ratio (about 60 g coffee per litre) is a common all-rounder. Go lower (1:15) for a stronger cup or higher (1:18) for a milder one. A kitchen scale gives far more consistent coffee than scoops, since bean density varies.

What this does

A coffee to water ratio calculator finds how much coffee or water you need for a given brew ratio, from a strong 1:15 to a mild 1:18.

How to use it

  1. Choose your brew ratio.
  2. Enter the coffee or water amount.
  3. Read the other in grams.
  4. Adjust the ratio to taste.

How it works

A 1:16 ratio (about 60 g per litre) is a popular all-rounder. One gram of water is about one millilitre, so the maths stays simple.

water = coffee × ratio (e.g. ×16)

Understanding your result

The ratio sets strength: a tighter ratio like 1:15 brews a bolder cup, while 1:18 is lighter, with 1:16 a reliable starting point. Dial it to taste, and keep the ratio fixed when you change batch size so the cup stays consistent from one brew to the next.

Example

At 1:16, 30 g of coffee needs about 480 g of water.

Sources & methodology

Last updated .

Frequently asked questions

What is a good coffee-to-water ratio?

A 1:16 ratio (about 60 g of coffee per litre of water) is a popular all-rounder. Use 1:15 for a stronger cup or 1:18 for a milder one.

Do I measure in grams or millilitres?

Grams are most consistent. One gram of water is about one millilitre, so a 1:16 ratio works out to roughly 16 ml of water per gram of coffee.

Why use a scale instead of scoops?

Bean size and roast change how much a scoop weighs, so the same scoop can vary a lot. Weighing the coffee gives a far more repeatable brew.

Is my data stored?

No. Everything is calculated locally in your browser.