The Proper Coffee to Water Ratio (Metric Style!)


Knowing how much coffee to brew is not as straightforward as it could be. A person might know how to make their personal dose of coffee in the morning, but when visitors come over and they need to make ten or twelve cups in the pot, they need some help with the math. If you are using metric measurements, this is a breeze! For English-style measurements, check out this other post.

Coffee by Cup
Brewing Ratio (The Metric Way)
Cups to Brew How Much CoffeeHow Much Water
1
11 grams200 ml
2
22 grams400 ml
444 grams800 ml
666 grams1.2 liters
888 grams1.6 liters
10110 grams2 liters
12132 grams2.4 liters

The “Golden Ratio” is 55 grams of coffee for every liter of water. According to the Specialty Coffee Association this will give you an acceptable cup of coffee. It is up to you to adjust your water to fit your cup needs and your ground coffee to fit your tastes. But that is just the beginning; if you really want to geek it up, I have some easy tips for you.

Coffee by cup chart
What is the correct amount of water?
Better Measuring
What is the correct amount of coffee?
Coffee by volume chart

What is the correct amount of water?

The first thing you might notice is that the table above says you are brewing 1 cup of coffee. Here is where some confusion may arise. A “cup” can mean different things depending on the circumstances. A cup of water by US measure is 8 fluid ounces. This is equal to about 237 ml. But wait a minute: A “cup” of coffee is 6 fluid ounces, about 177 ml. The reason for this discrepancy is because coffee is usually served in a “teacup” and a teacup traditionally holds six ounces. Now, if like me you like your coffee in a mug, that is usually going to come in at 300 – 350 ml depending on the size. A Starbucks Venti? Well, venti is the Italian word for twenty and 20 fluid ounces equals 600 ml.

FYI

Those little cups they serve you in a fancy restaurant are called a demitasse. Demitasse comes from the French words demi and tasse, which mean half and cup. That’s right, those little cups are 3 fluid ounces (Get it? Three is half of six, which makes it a half cup!). That works out to about 90 ml. Don’t even get me started on Imperial measures. It is little wonder that we run into difficulty when we try to brew a proper cup of coffee.

a selection of coffee cups and mugs
Compare these coffee cups and mugs.
Clockwise from the top they hold 300 ml, 350 ml, 75 ml, and 275 ml.
Wow… Deja vu!

Get the measurement right

Obviously, there is a large variation in the amount of liquid that might be found in a “cup.” To get our brewing ratio correct we must accurately determine how much water we are actually dealing with. That means we are going to have to break out a measuring cup to find nail down our numbers.

  • What is the volume of your cup?
  • What is the volume of your pot?
  • Those gradations on your pot? What are they measuring?
A partially filled glass coffee pot
What do the gradations on your coffee pot really mean?
Swiped from HulaDaddy.com

I know, the pot says “12,” but 12 what? 12 teacups or 12 US cups? Is it 12 restaurant size cups? Or maybe it is just 12 of whatever the guy who designed the pot had laying around. The bottom line is, until you measure it, you don’t really know. So get your units figured out and we will be ready for the second part of the ratio: the correct amount of coffee.

What is the correct amount of coffee?

measuring scoop and coffee beans
A scoop? Really? Until you know how much your coffee weighs,
a scoop is little more than a guess.

Using a volume measure like “spoonfuls” or “scoops” is not an accurate way to determine how much coffee you have. Beethoven is known to have insisted on 60 beans for each cup of coffee. Is that any better? Both of these methods fail to account for the fact that some coffees are less dense than others and all coffee beans are not the same size. “Two spoonfuls per cup” or “10 scoops per pot” is just not going to get the job done. If you want the right amount of coffee you must weigh it.

Remember, the “golden ratio brew” is 55 grams per liter of water. Which means that if you are brewing one of my 350 ml mugs in a pour over, you will need to use xx grams of coffee for the proper brew. So, break out the kitchen scale if you really want to get it right.

Brewing Ratio By Volume
Brewing Ratio (By Volume)
Cup SizeHow Much Coffee to UseWater
Demitasse (90 ml)5 grams90 ml
Teacup (180 ml)10 grams180 ml
200 ml11 grams200 ml
US cup (240 ml)13.2 grams240 ml
300 ml16.5 grams
300 ml
350 ml19.25 grams350 ml
1 liter pot55 grams1 liter

Basically, just multiply the amount of water (in ml) you are using by .055 to get the proper amount of coffee.

Of course, in the end, it is all a matter of taste. Brew a cup and see if it is all you hoped it would be. If it isn’t, then adjust the amount of coffee up or down to suit your taste. Once you have zeroed in on your brewing preferences, you can go back to the “spoonful” method. You will be able to estimate accurately how much coffee you need for your particular situation. I suggest checking your measurements when you switch coffees; every coffee is different from roast to roast and switching from a Sumatran Monsooned coffee to a strictly hard bean Guatemalan might make a big difference in the amount of coffee you need for a specific volume. A little time and care can go a long way toward improving your cup.

Coffee by cup chart
What is the correct amount of water?
Better Measuring
What is the correct amount of coffee?
Coffee by volume chart

Related Posts

The Proper Coffee to Water Ratio (American style)

Tim

I am Tim Bruno, a former Kona coffee farmer promoting the soon to be released Procaffeination: A Coffee Lover’s Dictionary and several other coffee-related products. I will soon be adding a YouTube channel to my efforts. Stay tuned!

Recent Content