How to Measure Caffeine in Coffee

Coffee is a popular drink and the biggest source of dietary caffeine. But do you really know how much caffeine is in a cup of coffee? Should you even worry about it? Read on to learn more.

An average cup of joe may have around 95 mg of caffeine. However, this amount varies among different drinks and range from almost zero to 500 mg.

The figures below will give you a rough idea of the caffeine in coffee.

  • Brewed Coffee (8 oz / 237 mL): 95-200 mg of caffeine
  • Latte (8 oz / 237 mL): 63-175 mg of caffeine
  • Decaffeinated Brewed (8 oz / 237 mL): 2-12 mg of caffeine
  • Espresso (1 oz / 30 mL): 47-75 mg of caffeine
  • Decaffeinated Espresso (1 oz / 30 mL): 0-15 mg of caffeine
  • Instant (8 oz / 237 mL): 27-173 mg of caffeine
  • Decaffeinated Instant (8 oz / 237 mL): 27-173 mg of caffeine

Check out our article If you want to know more about caffeine counts for each coffee drinks and beans from different regions.

What factors affect caffeine content?

The amount of caffeine in your cup depends on many factors. They include:

  • Type of coffee: The caffeine content can vary significantly between regularly brewed coffee, espresso, instant coffee, and decaf coffee.
  • Type of coffee beans: There are many varieties of coffee beans available, which may naturally contain different amounts of caffeine.
  • Roasting: Lighter roasts have more caffeine than darker roasts, although the darker roasts have a deeper flavor.
  • Serving size: “One cup of coffee” can range anywhere from 30–700 ml (1–24 oz), significantly affecting the total caffeine content.

Does espresso have more caffeine?

A typical cup of espresso (2-ounce serving) contains 45-75 mg of caffeine per ounce. Compare that to the drip coffee (served in a variety of sizes), and contains 20 mg of caffeine per ounce. You will notice that espresso will give you way more caffeine. See the table below for more information:

  • Espresso (2 oz): 150 mg Caffeine
  • Drip Coffee (12 oz): 240 mg Caffeine
  • Drip Coffee (16 oz): 320 mg Caffeine
  • Drip Coffee (20 oz): 400 mg Caffeine

As you can see, espresso has the most caffeine per ounce, but you will get more caffeine if you sip a large drip coffee. However, remember there are factors beyond size that determines the amount of caffeine you ingest (we mentioned them earlier)

Can you measure caffeine content?

If you want to test your coffee beans for the amount of caffeine it has, I am sorry to disappoint. Many companies have the capacity to measure the caffeine content in their drinks. They use a method called ultraviolet spectroscopy — which is very accurate but also expensive. 

There is also a chemical way to measure caffeine content in your coffee. It is a lengthy process that involves the use of different materials, some of which are toxic, like sodium hydroxide. That means there isn’t going to be any coffee left to enjoy when done. Learn more here about how Maximillian Du chemically measured caffeine in coffee and in other drinks. 

Does the roast level affect caffeine?

Some people insist dark roasted coffee has more caffeine. Others maintain that light roasts have more caffeine. Who is right? Here is what you need to know.

During the roasting process, coffee’s caffeine content remains relatively stable. What really changes is the taste and caffeine level per the beans’ weight and volume. This is because beans lose some of their moisture and overall mass when roasted.

Beans roasted dark or past the second crack will have a conspicuously lighter weight than light roasts. That decrease in density and mass is yet another reason why some coffee lovers believe dark roasted coffees are lacking in caffeine.

How do you minimize or maximize your caffeine intake?

The measurement and grind size of your beans dictates the amount of caffeine in your cup. Since dark roast coffees weigh less than light roast coffees, a pound of dark roast will include more beans than a pound of light. 

If you measure by weight, the dark roast coffees will have more caffeine. Whereas, if you measure your beans by volume, a heavier and denser light roast will produce more caffeine. For example, if you measured out 20 grams of dark and light-roasted beans, both will weigh the same, but the cup of the dark roast will have more caffeine because it requires extra beans. Sound confusing? You are not alone. I also had to reread a few more times!

Once you have your coffee measured, you can now focus on the water temperature, brew time, and grind levels. To explain this in the simplest form possible, the finer the grind, the longer the brew time, and the hotter the temperature, the more caffeinated your brew will be. 

Is caffeine something to worry about?

Caffeine is no cause of concern unless you exceed the recommended daily limit. Normally, consuming 400–600 mg/day of caffeine is healthy. However, it is good to note our bodies react differently. So it is good to experiment and see which amount is ideal for you. 

How do you extract caffeine from coffee?

To extract caffeine from coffee beans, they are washed in a solvent (a liquid capable of dissolving substances). This process transfers the caffeine from bean to liquid in a process known as extraction.

Conclusion

You shouldn’t be worried about your caffeine consumption if not going overboard. However, you need to be cautious if you have a condition that requires you to watch your caffeine intake. Consult your doctor if you suspect or your body reacts abnormally after sipping caffeinated drinks.

Overall, experiment with different amounts until sure of which amount of caffeine is ideal for you. 

nv-author-image

Self-proclaimed coffee drinker. I would, on a typical day, start my day by grinding my coffee with a manual grinder and use a French Press as a starter (2 cups), then a pour-over in the afternoon (4 cups). I had my fair share as a barista but I prefer to drink it, not serve it.