Answer firstThe ratio is “one part coffee to how many parts water”, and it sets strength. The formula is simple: water = dose × ratio. 1:15 is a handy default (stronger), 1:16 is balanced, 1:17–1:18 is light and tea-like, and espresso is about 1:2. Weigh, pick a ratio, calculate water, and the same ratio gives repeatable strength. Full cheat sheet below, just pour to it.
Coffee Ratios · brew → measure → master
One formula
Nothing to memorise but this:
water = dose × ratio
Example: 18g of coffee at 1:16 → water = 18 × 16 = 288g. Want it stronger, use 1:15 (270g); lighter, use 1:17 (306g). That’s it.
Pick a ratio → get water; 1:15 is the handy default
Ratio = the strength dial
Think of the ratio as a “strength” dial: smaller is stronger (1:15), larger is lighter (1:18). Grind and time are the “balance” dial for sour vs bitter. Keep them separate: set strength with ratio, then fine-tune balance with grind. The same ratio repeats the same strength across any cup size.
Ratio = strength grind/time = balance; same ratio = repeatable
Four steps to a cup
1
Choose the dose decide the grams of coffee (e.g. 15g).
2
Pick a ratio 1:15–1:17 for filter.
3
Calculate water water = dose × ratio.
4
Brew and taste too strong, raise the ratio; too weak, lower it.
Choose dose → pick ratio → calculate water → brew and taste
The ratio ladder
Strong to light, remember a few: espresso 1:2 (strongest), 1:15 strong filter, 1:16 balanced, 1:17–1:18 light / tea-like. Beginners are safest starting at 1:15 or 1:16.
Pouring by feel: no scale means no repeat, you can’t reproduce a good cup. Changing ratio and grind together: move two things and you can’t tell which helped, change one at a time. Wrong ratio for the method: espresso is 1:2, filter is 1:15–1:17, don’t apply an espresso ratio to pour-over.
No eyeballing · don’t change ratio and grind together · right ratio per method
Screenshot this cheat sheet to your phone and check it as you brew. Want to go further with staged pouring and fine-tuning? JWC classes turn a recipe into feel.
FAQ
How do I calculate the water?
Water = dose × ratio. 18g at 1:16 is 18 × 16 = 288g of water.
What ratio should a beginner use?
Start filter at 1:15–1:16. Use 1:15 for stronger, 1:17–1:18 for lighter and tea-like.
Is the same ratio the same cup?
It gives repeatable strength across cup sizes; fine-tune the sour-bitter balance with grind and time.
Does espresso use this ratio?
No. Espresso is about 1:2 (very strong); 1:15–1:18 is the filter range, don’t mix them.
Repeatable every time
Want steady strength you can fine-tune yourself?
From ratio to staged pouring and grind tweaks, a mentor turns a recipe into feel · from RM199 · real machines
