☕ Coffee-to-Water Ratio Calculator
Set your coffee-to-water ratio and enter either the coffee or the water you have, and get the exact amount of the other, for consistent coffee, cup after cup.
Coffee
30 g
Water
480 g / mL
The "golden ratio" is about 1:15 to 1:18 (coffee:water) by weight, lower is stronger. Water is measured by weight; 1 g ≈ 1 mL. Weighing beats scooping for consistency. 🔒 In your browser.
How the coffee-to-water ratio calculator works
Good coffee is about proportion. The tool uses a ratio of 1 gram of coffee to N grams of water: enter the ratio and one quantity, and it computes the other by multiplying or dividing. Water is measured by weight, which is why it’s given in grams (1 g of water ≈ 1 mL). So at a 1:16 ratio, 500 g of water needs 500 ÷ 16 ≈ 31 g of coffee; conversely 30 g of coffee calls for 30 × 16 = 480 g of water. Note the ratio counts the water that ends up in the cup, a little is always lost to the wet grounds, so brewing a touch more water than your target cup size is normal.
The widely-used “golden ratio” is roughly 1:15 to 1:18 by weight, a lower number (more coffee) brews stronger. Weighing your coffee and water, rather than scooping, is the single biggest step to consistent results. Grind size and brew method matter too.
Frequently asked questions
What is the golden ratio for coffee?
About 1 gram of coffee to 15-18 grams of water by weight (often written 1:15 to 1:18). 1:16 is a popular balanced starting point; use more coffee (a lower ratio) for a stronger cup.
How much coffee for one cup?
For a ~250 g (250 mL) cup at a 1:16 ratio, use about 15-16 g of coffee. Adjust the ratio to taste, 1:15 is stronger, 1:17-18 is lighter.
How much coffee per litre of water?
At a 1:16 ratio, one litre (1000 g) of water needs about 62 g of coffee. At 1:15 that’s 67 g, and at 1:18 about 56 g. Enter the water and the tool gives the coffee.
Why weigh coffee and water instead of using scoops?
Scoops vary with grind and bean, so weighing is far more consistent. A cheap kitchen scale lets you hit the same ratio every time, which is the key to repeatable coffee.
Does this work for any brew method?
The ratio is a starting point for pour-over, drip, French press and more. Different methods and grind sizes shift the ideal ratio slightly, so tweak from here to taste.
How do I make my coffee stronger or weaker without changing the amount?
Change the ratio, not the cup size. A lower number (more coffee per unit water), say 1:14, brews stronger; a higher number like 1:18 brews lighter. Keep the water fixed and let the tool recalculate the coffee, that isolates strength from how much you're making.
Is coffee-to-water ratio the same as strength or extraction?
Not quite. The ratio sets the brew's strength (how concentrated it is), while extraction, how much flavour is pulled from the grounds, is governed mainly by grind size, water temperature and brew time. You can hit the same ratio yet get sour or bitter coffee if the extraction is off, so treat the ratio as one of several dials.