Coffee to Water Ratio Calculator
Find the exact grams of coffee and water for any brew ratio, batch size, or number of cups.
:1
I know the
g
Water: 320 g (320 ml)
1 : 16
ratioCoffee
5.9%
Water
94.1%
- 1
Water at 1 ∶ r
20 × 16 = 320Coffee amount was entered directly; the ratio determines the water needed. - 2
Coffee grounds
20
How does this calculator work?
For a 1:r brew ratio, multiply coffee grams by r to get water grams, or divide water grams by r to get coffee. From cups, water = cups × 236.6 ml (≈ grams), then coffee = water ÷ r. The golden ratio is about 1:16, so 20 g coffee needs 320 g water.
Formula
How this is calculated
A brew ratio is written 1 : r, meaning one part coffee to r parts water by weight. The "Brew ratio" input is that r value; the widely recommended golden ratio is about 1:16, while 1:15 brews stronger and 1:18 brews weaker. Choosing what you already know lets the calculator solve in any direction.
If you enter coffee grams, water is coffee × r. If you enter water (grams or millilitres, since 1 ml of water weighs about 1 g), coffee is water ÷ r. If you enter cups, each US cup is treated as 236.6 ml ≈ 236.6 g of water, so total water = cups × 236.6 and coffee = water ÷ r. The donut shows the coffee-to-water split and the stat grid reports both water mass and volume plus the total brew mass.
All values must be positive and the ratio must be greater than zero, otherwise the result is hidden. The 1 ml ≈ 1 g equivalence is accurate for water near room temperature; brewing also loses a little water to absorption and evaporation, so brewed yield is slightly less than the total mass shown.
Frequently asked questions
The golden ratio is roughly 1:16 to 1:18 — one gram of coffee for every 16 to 18 grams of water. This calculator defaults to 1:16, a balanced starting point you can dial stronger (lower r) or weaker (higher r) to taste.
Water has a density very close to 1 g/ml at normal brewing temperatures, so 250 ml of water weighs about 250 g. The calculator treats the two as equal, which is precise enough for any home or café brew.
A US cup is about 236.6 ml of water. At a 1:16 ratio that is roughly 14.8 g of coffee per cup. Enter your number of cups and ratio to get the exact grams.
Also known as
TG we-Calculate Editorial Team. (2026). Coffee to Water Ratio Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/coffee-to-water-ratio-calculator
TG we-Calculate Editorial Team. "Coffee to Water Ratio Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/coffee-to-water-ratio-calculator.
TG we-Calculate Editorial Team, "Coffee to Water Ratio Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/coffee-to-water-ratio-calculator
@misc{wecalculate_coffee_to_water_ratio_calculator, title = {Coffee to Water Ratio Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/coffee-to-water-ratio-calculator}}, year = {2026}, note = {TG we-Calculate} }
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