Coffee Ratio Calculator
The difference between good coffee and disappointing coffee is usually not the beans, the grind, or the water - it's 3 grams. Brewing is a ratio game: grams of coffee times your ratio equals grams of water, and the whole specialty world lives between 1:15 (bold) and 1:18 (light). This calculator runs the math both directions - 'I have 500ml of water, how many beans?' and 'I weighed out 30g, how much water?' - so the scale becomes the best upgrade your kitchen ever took.
The verdict line reads your ratio back in plain language - strong, balanced, or tea-like - and the note carries the two adjustments that actually fix a cup: grind coarser for bitter, finer for sour. Your recipe is remembered for tomorrow morning, the result rides in the tab title while you pour, and the share link sends the exact recipe to whoever keeps asking why your coffee tastes better.
How to use
- Pick a direction: know your water (most brewing) or know your coffee (pre-weighed).
- Enter the amount and a ratio - 1:16 is the universal starting point.
- Brew, taste, then move the ratio one notch: 1:15 for more punch, 1:17 for lighter.
Frequently asked questions
What is the golden ratio for coffee?
The specialty-coffee standard sits at 1:16 to 1:18 coffee to water by weight - about 30-31g of coffee per 500ml. 1:15 and below reads strong and heavy (good for French press with milk), 1:17 is where most pour-over dialed-in cups live, and past 1:19 extraction struggles to keep up with the dilution and the cup turns thin and papery.
Why weigh coffee instead of using scoops?
A 'tablespoon' of coffee can weigh 4g or 7g depending on grind, roast and how heaped it is - a spread wide enough to change the cup noticeably. Ten dollars of scale removes the biggest variable in brewing, which is why every serious recipe you've ever seen is written in grams: weight is the only honest unit.
Does the ratio change for espresso or cold brew?
Yes - they're different games: espresso runs near 1:2 in 25-30 seconds (a 18g dose to a 36g shot), and cold brew is a concentrate near 1:8 that gets diluted before serving. This calculator covers the immersion and pour-over family where 1:14-1:18 rules; for espresso, dose and yield are the two numbers to fix first.
My coffee tastes sour/bitter - is it the ratio?
Probably the grind, and the ratio can compensate: sour-and-thin means under-extraction, so grind finer or use more coffee (lower ratio); bitter-and-dry means over-extraction, so grind coarser or use less (higher ratio). Change one variable at a time by a small step - the calculator keeps the math honest while your palate finds the sweet spot.