Coffee Ratio Calculator

About the Coffee Ratio Calculator

The single biggest improvement most people can make to their coffee is not a new machine or more expensive beans, but measuring. Coffee that tastes bitter and harsh, or thin and sour, is very often simply the wrong amount of coffee for the water. Professional baristas and coffee competitions describe every brew by its ratio — grams of coffee to grams of water — because it is the one number that makes a good cup repeatable.

This coffee ratio calculator works out how much ground coffee you need for any amount of water, for pour-over, French press, drip machines, AeroPress, cold brew and espresso. It gives the coffee in grams and tablespoons, the amount of coffee you will end up with in the cup, and the usual grind size and brew time for the method. You can also enter your own ratio.

How to Use the Coffee Ratio Calculator

Choose the brew method.

Enter the water in millilitres. A millilitre of water weighs a gram, so grams on a kitchen scale work equally well. For espresso, enter the weight of the shot you want in the cup.

To use your own ratio, enter it as the second number: 14 for 1:14. Leave it at 0 for the method's standard ratio.

How the Coffee Is Worked Out

  coffee   =  water ÷ ratio
  brewed   ≈  water − 2 × coffee    (wet grounds hold about twice their weight)
  1 level tablespoon of ground coffee  ≈  5 g

  espresso:  dose  =  shot in the cup ÷ 2

Step-by-Step Example

500 ml of water for pour-over at 1:16.

  Coffee:       500 ÷ 16              =  31.3 g  (about 6¼ tablespoons)
  In the cup:   500 − 2 × 31.3        =  about 438 ml

Cold brew with 1 litre of water at 1:8.

  Coffee:       1,000 ÷ 8             =  125 g
  Concentrate:  1,000 − 2 × 125       =  about 750 ml, diluted 1:1 to serve

Standard Ratios by Method

These are starting points. Most filter coffee is brewed somewhere between 1:15 and 1:18, and the "golden ratio" promoted by coffee associations sits around 1:16 to 1:18.

Strength Versus Extraction

Two different things decide how coffee tastes. Strength is how concentrated the drink is — mostly controlled by the ratio. A smaller ratio number, such as 1:14, makes stronger coffee; a larger one, such as 1:18, makes lighter coffee. Extraction is how much flavour has been pulled out of the grounds — controlled by grind size, water temperature and time. Under-extracted coffee tastes sour and thin; over-extracted coffee tastes bitter and dry. If your coffee is strong but sour, grind finer; if it is weak but bitter, use more coffee and a coarser grind.

Why Weigh Instead of Using Scoops

A scoop or tablespoon holds a different weight of coffee depending on the roast, the grind and how it is packed. Dark roasts are less dense than light ones, and fine grounds pack more tightly than coarse. A tablespoon may hold anywhere from 4 to 7 grams. A kitchen scale accurate to a gram costs little and makes each cup consistent; many pour-over brewers weigh the water too, directly on the scale.

Water Temperature and Quality

Water just off the boil, around 90 to 96 °C (195 to 205 °F), suits most hot brewing methods. Boiling water poured straight onto a dark roast can extract harsh flavours. Coffee is about 98 percent water, so water that tastes of chlorine or is very hard will make noticeably worse coffee; filtered water often helps.

Brewing for a Group

To make coffee for several people, multiply the water by the number of mugs. A typical mug holds 250 to 350 millilitres. For eight 250 millilitre mugs at 1:16 you need 2 litres of water and 125 grams of coffee. Large drip machines and French presses are the easiest way to brew that much at once.

Choosing Beans and Grinding Fresh

Ground coffee loses aroma within minutes, and most of its flavour within days, as the volatile compounds that make it smell wonderful escape into the air. Grinding beans just before brewing makes a bigger difference than almost any other change. A burr grinder, which crushes beans to an even size, is better than a blade grinder, which chops them into a mix of dust and chunks that extract unevenly. Buy whole beans in quantities you will use within two to four weeks of the roast date, and store them in an airtight container away from light and heat rather than in the fridge, where they pick up moisture and odours.

Tasting and Adjusting

Change one thing at a time. Keep the ratio fixed while you adjust the grind until the coffee tastes sweet and balanced, then change the ratio to set the strength you like. Note what works in a notebook or on your phone so the next bag of beans starts from a good recipe.

Understanding Your Result

Coffee is the weight of ground coffee to use.

Ratio confirms the ratio and method.

In tablespoons gives an approximate measure without a scale.

Water and yield shows the water and roughly how much coffee you will get.

Grind and time gives the usual grind and brew time.

Worth knowing explains how to adjust the strength.

When Should You Use This Calculator?

Trying a new brewer or method.

Brewing a larger or smaller batch than usual.

Making cold brew in a big jar.

Dialling in espresso by weight.

Getting consistent coffee every morning.

Common Mistakes

Measuring by scoop instead of by weight.

Using the wrong grind for the method.

Changing the ratio to fix extraction problems.

Forgetting that grounds hold water, so the cup is smaller than expected.

Drinking cold brew concentrate undiluted by accident.