What is a coffee to water ratio?
A brew ratio says how much water you use for each part of coffee, by weight. At 1:16, every gram of coffee gets 16 grams of water. Because 1 ml of water weighs about 1 g, you can read the water side in milliliters too. The ratio is what sets the strength of the cup: less water per gram gives a stronger brew, more water a lighter one.
This coffee ratio calculator works it out in three directions. Enter the water and get the coffee, enter the coffee you have and get the water, or enter a number of cups and their size. It also shows a rough tablespoon count and how much coffee ends up in the cup, since wet grounds hold back some of the water.
Example: 500 ml of water at 1:16 needs 500 ÷ 16 = 31.25 g of coffee. Brewing with 20 g of coffee at 1:15 takes 20 × 15 = 300 ml of water.
Starting ratios by brew method
Every number below is a starting point, not a rule. Beans, roast and taste differ, so brew once at the suggested ratio, then adjust.
| Brew method | Start at | Common range | Grind | Brew time |
|---|---|---|---|---|
| Pour over / drip | 1:16 | 1:15 to 1:17 | Medium to medium fine | 3 to 4 min |
| French press | 1:15 | 1:12 to 1:16 | Coarse | About 4 min |
| AeroPress | 1:14 | 1:12 to 1:16 | Fine to medium | 1 to 2 min |
| Cold brew concentrate | 1:5 | 1:4 to 1:8 | Coarse | 12 to 24 h |
| Cold brew, ready to drink | 1:10 | 1:8 to 1:12 | Coarse | 12 to 24 h |
| Espresso | 1:2 | 1:1.5 to 1:3 | Fine | 25 to 30 s |
| Moka pot | 1:10 | 1:7 to 1:10 | Fine to medium fine | 4 to 5 min |
- Espresso is measured by output weight: grams of dry coffee in, grams of liquid espresso out. 18 g in and 36 g out is 1:2.
- Cold brew concentrate at 1:5 is diluted before drinking, often 1:1 with water or milk. Brew at about 1:10 if you want to drink it straight.
- AeroPress works well at 1:14 as a full cup. Some recipes brew stronger at about 1:12 and top up with hot water afterwards.
- Moka pot doses are set by the basket: fill it level without tamping and fill the base with water up to the valve.
Why weigh instead of using scoops
A tablespoon of ground coffee holds roughly 5 to 7 g, depending on the grind, the roast and how you fill it. Dark roasts are lighter per spoon, fine grinds pack denser. That spread is big enough to change the strength of your cup noticeably, which is why the calculator treats tablespoons as an approximate helper only. A small kitchen scale with 0.1 g steps makes your coffee repeatable from day to day.
Grind size
Grind and ratio work together. A finer grind exposes more surface, so water pulls flavor out faster. Short brews like espresso need a fine grind, long immersion brews like French press and cold brew need a coarse one so they do not turn bitter or muddy. If your coffee tastes sour and thin, try a finer grind. If it tastes bitter and dry, go coarser. Keep the ratio the same while you test the grind, so you only change one thing at a time.
Water temperature
For hot coffee, water from about 195 to 205°F (90 to 96°C) is the range most brew guides recommend. Without a thermometer, let boiling water rest for about 30 seconds. Darker roasts often taste better at the cooler end, lighter roasts at the hotter end. Cold brew uses cold or room temperature water and makes up for it with time, usually 12 to 24 hours in the fridge.
Stronger or weaker coffee
The strength slider moves the ratio in steps of about 5%. One step stronger turns 1:16 into 1:15.2, three steps turn it into 1:13.6. If you like the taste but not the strength, change the ratio. If the strength is right but the taste is off, change the grind or the brew time instead.
How to use the coffee ratio calculator
- 1Pick your brew method. The ratio field fills in a typical starting point that you can edit.
- 2Choose metric or US units, then enter your water, your coffee, or the number of cups and the cup size.
- 3Move the strength slider if you like your brew stronger or weaker, then weigh the coffee and water shown and brew.
Frequently asked questions
What is the best coffee to water ratio?
There is no single best ratio, but 1:16 is the most common starting point for pour over and drip coffee: 1 g of coffee for every 16 g (or ml) of water. French press often tastes better a bit stronger at 1:15, and espresso uses a much tighter 1:2. Start there, then move one step at a time until the cup tastes right to you.
How many grams of coffee per cup?
For a US cup of 8 fl oz (236.6 ml) at 1:16, you need about 15 g of coffee. That is roughly 2 to 3 level tablespoons of ground coffee. Many mugs hold 12 fl oz or more, so check what your cup actually holds and enter that size in the calculator.
How much coffee for a 12 cup coffee maker?
A "cup" on a coffee maker is usually 5 to 6 fl oz, not 8. Twelve of those make 60 to 72 fl oz of water, so at 1:16 you need about 110 to 135 g of coffee, roughly 16 to 22 level tablespoons depending on the grind. Switch the calculator to cups, pick the coffee maker cup size and enter 12.
Why is cold brew so strong at 1:5?
A 1:5 cold brew is a concentrate. It is meant to be diluted before drinking, often 1:1 with water or milk, or more if you like it lighter. If you would rather drink it straight from the jar, brew at about 1:10 instead.
My coffee is bitter or sour even at the right ratio. Why?
The ratio sets the strength, but the taste also depends on extraction: grind size, water temperature and brew time. Sour, thin coffee is usually under-extracted, so grind a bit finer or brew a bit longer. Bitter, harsh coffee is often over-extracted, so grind coarser or shorten the brew. Change one thing at a time.