Coffee Ratio Calculator

1. Choose Water amount, Coffee amount, or Brew ratio from Solve for.
2. Choose grams (g) or ounces (oz) from Weight unit.
3. Fill in the other two fields, Coffee amount, Water amount, and Ratio (1 : N).
4. Click Calculate to show the solved value, formula, assumptions, and calculation rows.
5. Use Copy result or Download result (.txt) to take the text off the page.

Coffee-to-water ratio formula and example

A ratio of 1 : N means one part coffee to N parts water by weight. The calculator uses one of these three relationships, depending on the choice in Solve for:

• Water = Coffee x N
• Coffee = Water / N
• N = Water / Coffee

Coffee amount: 20 g
Ratio (1 : N): 16
Water amount: 320.00 g

With 20 g of coffee and an N value of 16, Water = Coffee x N gives 320.00 g. The ratio has no unit. Coffee amount and Water amount use the selected Weight unit.

What Solve for changes

Select Water amount when Coffee amount and Ratio (1 : N) are known. Select Coffee amount when Water amount and Ratio (1 : N) are known. Select Brew ratio when Coffee amount and Water amount are known.

The field for the selected answer is hidden. The two fields used for the calculation stay visible. If you change an input or selection, the current result is hidden until you click Calculate again.

Grams, ounces, valid inputs, and limits

Weight unit labels Coffee amount and Water amount as grams or ounces. Switching the unit changes the label and leaves the numbers as entered. The calculator assumes 1 gram water = 1 milliliter water. Enter coffee and water as weights; the calculator has no fields for cups, spoons, or other volume entries.

The two fields you enter must contain finite numbers greater than zero. A blank, invalid, infinite, or zero value produces an error. Enter the N value in Ratio (1 : N), such as 16 for 1 : 16.

The calculation uses only the numbers you enter. It does not recommend a ratio, include water absorbed by coffee grounds, estimate final brewed liquid yield, fetch brew guides, or apply a coffee association's or roaster's convention. The script processes the values in the browser and does not submit them.

Click Reset to restore Solve for to Water amount, Weight unit to grams (g), Coffee amount to 20, Water amount to 320, and Ratio (1 : N) to 16. Reset also clears errors and hides the result.

Where coffee ratio calculations come up

For a 1 : 16 brew with 20 g of coffee, enter 20 in Coffee amount and 16 in Ratio (1 : N), then calculate 320 g of water.

To check a recipe with a fixed water weight, choose Brew ratio, enter Coffee amount and Water amount, and record the displayed N value.

When another food calculator fits better

Use this page when the calculation involves coffee amount, water amount, and brew ratio. The broader Food Calculators category is a better starting point when the job also involves dough, brine, nutrition, costing, or recipe math.

For a complete recipe with coffee ratio alongside other recipe calculations, use the Recipe Calculator. For changing volume, weight, or temperature units, use the Cooking Conversion Calculator. For scaling an ingredient list to a different serving count, use the Recipe Scaling Calculator.

Frequently asked questions