Drinks
Coffee to Water Ratio Calculator
For pour over coffee, the National Coffee Association gives 1 gram of coffee to 13 to 16 grams of water. At 1 to 16, 500 milliliters of water takes about 31 grams of coffee. For French press its range is 1 to 10 through 1 to 16. Enter your water or your coffee below.
Result
Enter how much water or coffee you have.
Show the math
Coffee to water chart
| Water | Pour over (1:16) | Drip machine (1:15) | French press (1:14) |
|---|---|---|---|
| 250 ml | 15.6 g | 16.7 g | 17.9 g |
| 350 ml | 21.9 g | 23.3 g | 25 g |
| 500 ml | 31.3 g | 33.3 g | 35.7 g |
| 750 ml | 46.9 g | 50 g | 53.6 g |
| 1000 ml | 62.5 g | 66.7 g | 71.4 g |
How the calculator works
A brew ratio compares the weight of water with the weight of coffee. A ratio of 1 to 16 means 16 grams of water for each gram of coffee.
If you know how much water you are using:
coffee = water / ratio
If you know how much coffee you have:
water = coffee x ratio
Water is easy to weigh because 1 milliliter weighs 1 gram. So 500 milliliters at 1 to 16 is 500 / 16 = 31.25 grams of coffee. If you enter water in cups or fluid ounces, the calculator converts it to milliliters first.
Worked example
You want two mugs of pour over, about 350 milliliters each.
- Water: 2 x 350 = 700 milliliters.
- Coffee at 1 to 16: 700 / 16 = 43.75, so 44 grams.
The other way round: you have 30 grams of beans left and a French press.
- At 1 to 14: 30 x 14 = 420 milliliters of water.
Starting ratios by method
The calculator loads a starting ratio when you pick a brew method.
- Pour over: 1 to 16. The National Coffee Association gives 1 to 13 through 1 to 16.
- French press: 1 to 14. The association gives 1 to 10 through 1 to 16.
- Drip machine: 1 to 15.
The ranges are the association’s. The single number the calculator opens with is this site’s pick inside each range, and you can type your own in the ratio box.
Drip is the odd one out. The association gives it by the spoon, 1 to 2 tablespoons of ground coffee for every 6 ounces of water, and not by weight. The calculator starts drip at 1 to 15, inside the pour over range, because a drip machine is an automated pour over.
The same pages give the rest of the method: a medium grind for pour over and drip, a coarse grind like rock salt for French press, water at 93 °C give or take 3 degrees, and contact times of 2 to 4 minutes for pour over, about 4 minutes for French press and about 5 for drip.
How the ratio changes the cup
Lower numbers are stronger. The same 500 milliliters of water takes:
- 1 to 13: 38.5 grams of coffee
- 1 to 14: 35.7 grams
- 1 to 15: 33.3 grams
- 1 to 16: 31.3 grams
That is a spread of about 7 grams across the whole pour over range, which is why a scale helps. The difference between a heaped scoop and a level one is of the same order.
Ratio controls strength: how concentrated the coffee is. It does not fix a brew that tastes sour or bitter. The National Coffee Association ties those to the grind: go finer if the coffee tastes flat or watery, and coarser if it tastes bitter or sour. If the strength is right but the taste is off, change the grind before you change the ratio.
Common brew sizes
At 1 to 16, the usual pour over starting point:
- 250 milliliters, a small cup: 15.6 grams of coffee
- 350 milliliters, a mug: 21.9 grams
- 500 milliliters, two small cups: 31.3 grams
- 1 liter, a full carafe: 62.5 grams
If you think in fluid ounces, an 8 ounce cup is 237 milliliters and takes 14.8 grams, and a 12 ounce mug is 355 milliliters and takes 22.2 grams.
For a stronger or lighter cup, change the ratio and read the new amount.
Water in and coffee out
The ratio uses the water you pour in, not the coffee that ends up in the cup. Grounds hold on to some of the water, so 500 milliliters in gives a little less than 500 out. If you need a full mug, brew with slightly more water than the mug holds.
Brewing for a crowd
Ratios scale in a straight line, so a big batch uses the same math. For a 1.5 liter drip machine at 1 to 15: 1,500 / 15 = 100 grams of coffee. The chart above lists common volumes for each method.
Tips and common mistakes
Measure the water you pour, not the size of the pot. A “12 cup” coffee maker does not use 12 US measuring cups. The marks on the tank are smaller servings.
Change one thing at a time. If a cup is too weak, drop the ratio by one and brew again before touching the grind.
Keep the ratio when you change the amount. If 20 grams to 320 milliliters tastes right, 40 grams to 640 will taste the same.
Write down the ratio you like for each brewer. Once you have it, the calculator turns it into amounts for any number of cups.
Frequently asked questions
How much coffee do I need for 1 liter of water?
At a 1 to 16 ratio, 62.5 grams. At 1 to 15, about 67 grams. Divide the water in milliliters by the ratio to get grams of coffee.
How much coffee do I need for one mug?
A 350 milliliter mug at 1 to 16 takes about 22 grams of coffee. Brew with a little more water than the mug holds, because the grounds keep some of it.
What does a 1 to 16 ratio mean?
It means 16 grams of water for every gram of coffee. Since a milliliter of water weighs a gram, 20 grams of coffee at 1 to 16 needs 320 milliliters of water.
How do I make coffee stronger?
Use a lower ratio, which means more coffee for the same water. Moving from 1 to 16 down to 1 to 14 puts about 14 percent more coffee in the same water. Change the ratio in the calculator and the amounts update.
Why measure coffee in grams instead of scoops?
A scoop measures volume, and the weight of a scoop changes with the roast and the grind. Weighing gives you the same amount of coffee every time, so the only thing that changes the taste is what you choose to change.