This coffee calculator converts between water and ground coffee amounts using common brew ratios or a custom ratio.
Food
Coffee to Water Ratio Calculator
Calculate coffee and water amounts for common brewing ratios.
Calculator
About this calculator
Formula notes
For ratio 1:N, coffee grams = water mL / N, or water mL = coffee grams x N.
Worked examples
- Example: 300 mL of water with a general regular 1:18 ratio needs about 16.7 g of coffee.
- Using a 1:15 strong drip ratio, 45 g of coffee needs 675 mL of water.
How to use it
- Choose a brew method and strength, or select Custom ratio.
- Choose whether you know the water or coffee amount.
- Enter that amount and read the missing amount plus the ratio.
Frequently asked questions
Do the preset ratios change with strength?
Yes. Strong settings use less water per coffee part for most methods.
Can I use my own ratio?
Yes. Choose Custom ratio and enter the water parts per coffee part.
Limits and interpretation
- The preset ratios are taste guidelines, not extraction-yield measurements; grind size, water temperature, brew time, and bean density still affect strength.
- Water and coffee amounts are converted to mL and g; cup sizes and ice (for cold brew) are not modeled.