Coffee Ratio Calculator
Enter how much coffee you want to brew, pick your brewing method and preferred strength, and the calculator instantly shows how many grams of ground coffee and millilitres of water you need. Switch to the reverse mode to start from a fixed amount of coffee and find the right water volume. Results update as you type, so you can dial in your ratio without any mental arithmetic.
Formula
Worked example
Pour over at average strength uses a 1:16 ratio. For 300 ml of water: 300 ÷ 16 = 18.75 g of ground coffee. Rounding to 19 g is fine. To reverse: if you have 20 g of coffee, multiply by 16 to get 320 ml of water.
What is a coffee-to-water ratio and why does it matter?
A coffee-to-water ratio expresses how many grams of water you use for every gram of ground coffee. Written as 1:X, it means one part coffee to X parts water by weight. For example, a 1:16 ratio means 1 g of coffee for every 16 g (or ml) of water. The ratio is the single biggest variable you control in brewing: too much water and the coffee tastes weak and sour; too little and it turns bitter and harsh. Professional baristas rely on ratios rather than scoops because a tablespoon of finely ground espresso roast is much denser than a tablespoon of coarsely ground light roast, so volume is unreliable. Measuring by weight with a kitchen scale gives results that are consistent across roasts, grind sizes, and even different bags of the same coffee.
Ratio ranges by brewing method
Different methods extract differently, so they use different ratios. Pour over and autodrip sit around 1:15 to 1:17 for most tastes, with 1:16 as the Specialty Coffee Association "Golden Cup" baseline. French press works well at 1:13 to 1:17 because the full-immersion steep extracts more efficiently than a flow-through method. Cold brew uses a much shorter ratio - commonly 1:5 to 1:10 - because the final concentrate is usually diluted with water or milk before drinking. Moka pot also uses a shorter ratio (1:7 to 1:10) because the pressurised steam extracts aggressively. Espresso is the outlier: the stated ratio (1:1.5 to 1:3) refers to the dry coffee dose versus the liquid espresso in the cup, not the water in the boiler, so it is not directly comparable to drip ratios.
How to adjust for strength and taste
Strength and extraction are related but different. Strength is the concentration of dissolved coffee solids in your cup - more coffee or less water makes it stronger. Extraction is how much of the coffee is dissolved from the grounds - controlled mainly by grind size, water temperature and contact time. The fastest way to make a brew stronger is to increase the dose (use more coffee for the same water), which moves you toward a lower ratio number. The fastest way to change the flavour character - more fruity and bright or more bitter and heavy - is to adjust the grind. Use this calculator to lock in the ratio first, then fine-tune grind and temperature to hit the flavour you want.
Measuring coffee: grams versus tablespoons
Many recipes quote tablespoons or scoops, but weight is always more accurate. A standard tablespoon of coffee is roughly 5 to 7 g depending on how coarsely the beans are ground and how firmly the spoon is filled. If you do not own a scale, a level tablespoon per 100 ml of water is a reasonable starting point for drip coffee. For espresso, a level tablespoon of very fine grounds packs to about 7 g, so a double shot typically uses 2 to 2.5 tablespoons. The calculator outputs grams and millilitres by default, with an imperial option for fluid ounces, because weight-based brewing consistently produces better results than volume-based brewing.
Coffee-to-water ratios by brewing method
| Method | Ratio (1:X) | Grind size | Brew time |
|---|---|---|---|
| French Press | 1:15 | Coarse | 4 min |
| Pour Over / V60 | 1:16 | Medium-fine | 3-4 min |
| Cold Brew | 1:8 | Coarse | 12-24 hr |
| Autodrip | 1:16 | Medium-fine | 5-8 min |
| AeroPress | 1:14 | Medium-fine | 1-2 min |
| Chemex | 1:16 | Medium-coarse | 4-5 min |
| Siphon | 1:14 | Medium-fine | 1-2 min |
| Moka Pot | 1:8 | Fine | 5-10 min |
| Espresso (normale) | 1:2 | Extra fine | 25-30 sec |
| Espresso (ristretto) | 1:1.5 | Extra fine | 20-25 sec |
| Espresso (lungo) | 1:3 | Extra fine | 30-40 sec |
Standard ratios (1:X, meaning 1 g coffee per X g/ml water) for each method at average strength. Adjust to taste.
Frequently asked questions
What is the standard coffee-to-water ratio?
The Specialty Coffee Association recommends a "Golden Cup" ratio of roughly 1:18, meaning about 55 g of coffee per litre of water, for brewed drip coffee. In practice most baristas use 1:15 to 1:17. The right ratio depends on your brewing method, grind size, and personal taste, and this calculator lets you dial in any combination.
How many grams of coffee per cup?
For a standard 8 fl oz (237 ml) cup of drip coffee using a 1:16 ratio, you need about 15 g of ground coffee. At 1:15 you need about 16 g, and at 1:17 about 14 g. For a stronger brew at 1:13, you would use about 18 g per cup. This calculator works out the exact amount for any ratio and cup size.
What is the best ratio for French Press?
A ratio of 1:15 (about 67 g per litre) is a common starting point for French Press. Because immersion brewing is efficient, many people prefer a slightly lower ratio (more water) than they would for pour over. Try 1:17 for a lighter cup and step down toward 1:12 if you prefer something bold.
How does the cold brew ratio work?
Cold brew concentrate is typically brewed at a 1:5 to 1:8 ratio, then diluted 1:1 with water or milk before drinking. That means your final served cup is effectively around 1:10 to 1:16. If you prefer a ready-to-drink cold brew (no dilution), use a 1:8 to 1:10 ratio. The calculator shows the ratio used during brewing, not after dilution.
Why is the espresso ratio different from drip coffee?
For espresso, the ratio describes the relationship between the dry coffee dose and the liquid shot in the cup. A standard espresso (normale) is 1:2, meaning 18 g of coffee produces 36 g of espresso. A ristretto is shorter (1:1.5) and a lungo is longer (1:3). This is not comparable to drip ratios because the water used in the boiler is much more than the shot volume, much of it staying in the puck and machine.
Can I use this calculator to work backwards from coffee to water?
Yes. Switch the mode to "Water from coffee" and enter how many grams (or ounces) of ground coffee you have. The calculator multiplies by the ratio denominator to tell you exactly how much water to use. This is handy when you have a fixed amount of beans left in the bag.