Coffee Ratio Calculator
20 g of coffee at a 1:16 pour over ratio needs 320 g (320 ml) of water. The SCA Golden Cup standard of 55 g per liter is 1:18.18, which is 55 g of coffee for 1,000 g of water.
How to use
- Pick a brew method. The ratio box fills with a typical value, and you can type your own.
- Choose "Coffee to water" to enter your beans in grams, or "Water to coffee" to enter your water in g, ml or fl oz.
- Read the amount, the strength in grams per liter and the usual range for that method.
- For pour over, set the number of pours to see a bloom and pour schedule with the water to add and the running total on the scale.
How it works
A ratio of 1:16 means 1 part coffee to 16 parts water by weight. Water = coffee x ratio, and coffee = water / ratio. Strength in grams per liter = 1,000 / ratio.
The SCA Golden Cup standard describes a brew ratio of about 55 grams of coffee per liter of water. That is 1,000 / 55 = 1:18.18. Many people brew stronger than this, for example 1:15 to 1:17 for pour over, which is 59 to 67 g per liter.
Water is treated as 1 g per ml, and 1 US fl oz as 29.57 ml. Hot water is slightly lighter per ml, so for the best accuracy weigh the water in grams on a scale.
Pour over schedule: the bloom uses 2 times the coffee weight in water and lasts 40 seconds (a common range is 30 to 45). The remaining water is split into equal pours, one every 30 seconds. For 20 g and 320 g in 2 pours that is 40 g at 0:00, then 140 g at 0:40 (180 g on the scale) and 140 g at 1:10 (320 g).
Ratios are starting points. Roast, grind size, water temperature and taste change the best number, so adjust by 1 or 2 parts and keep what you like. Espresso ratio here means coffee dose to liquid in the cup, not water in the machine.
Typical ratios by method
The ranges are common brewing conventions rather than standards, except the SCA Golden Cup figure of about 55 g per liter. The default for each method is a midpoint.
| Method | Ratio range | Default | g per liter at default |
|---|---|---|---|
| Pour over | 1:15 to 1:17 | 1:16 | 63 |
| French press | 1:12 to 1:15 | 1:13 | 77 |
| AeroPress | 1:12 to 1:16 | 1:14 | 71 |
| Cold brew concentrate | 1:4 to 1:8 | 1:6 | 167 |
| Espresso (coffee to liquid) | 1:1.5 to 1:3 | 1:2 | 500 |
| SCA Golden Cup | 1:18.18 | 1:18.18 | 55 |
FAQ
What is the best coffee to water ratio?
There is no single best ratio. The SCA Golden Cup standard is about 1:18 (55 g per liter), while many people use 1:15 to 1:17 for filter coffee. Start in that range and change it by taste.
How much coffee for one cup?
A 250 ml cup at 1:16 takes about 15.6 g of coffee. Switch to "Water to coffee", enter 250 and read the beans. A scale is far more accurate than scoops.
Does the ratio change for iced or cold brew?
Cold brew concentrate is brewed strong, often 1:4 to 1:8, then diluted with water or milk. Iced coffee made hot over ice uses part of the water as ice, so brew with less water and let the ice make up the rest.
Why is espresso 1:2?
Espresso recipes are written as coffee dose to liquid yield, for example 18 g in and 36 g out. A shorter ristretto is nearer 1:1.5 and a longer shot 1:2.5 to 1:3.
How long should the bloom last?
About 30 to 45 seconds with roughly twice the coffee weight in water, so the grounds release gas before the main pours. Fresh coffee bubbles more and may like a longer bloom.