Calculate coffee and water from a brew ratio

Scale coffee mass or water volume from an explicitly chosen water-to-coffee ratio.

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ToolCoffee Ratio Calculator
Input
Output
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Preview

How it works

Known coffee grams are multiplied by the ratio to obtain water millilitres; known water is divided by the ratio to obtain coffee grams. The arithmetic uses the kitchen approximation that one gram of water occupies one millilitre.

Formula
water = coffee × water-to-coffee ratio
  • Method and ratio are both required because espresso beverage ratio and filter brew ratio describe different conventions.
  • No taste preference is assigned from the method name.

Worked example

20g of coffee for a pour-over
Scaling from the coffee amount at a selected 1:16 ratio
Input
											Method: Pour-over
Scale by: coffee
Amount: 20
Ratio: 16
Output
												Coffee grams: 20
Water millilitres: 320
Ratio used: 1:16
Method: Pour-over

When to use this

Pour-over recipes scale a selected ratio by dose, batch brewers convert litres into grounds, and espresso recipes separately compare dry dose with beverage yield.

Edge cases

  • Espresso commonly compares dry dose with beverage output mass, not input water, so its ratio should not be treated as a filter-brew water ratio.
  • A 1:16 selection means sixteen parts water for one part coffee by weight, not sixteen percent coffee.
  • Whole-millilitre water and 0.1 g coffee rounding can create a small ratio difference in tiny batches.

References