How to Measure Caffeine Content in Coffee?

Caffeine is a substance enriching almost every type of coffee, from creamy lattes to mochas. While it’s completely harmless when consumed in moderation, over-consumption of caffeine can lead to migraine and heart diseases.

If you are sensitive to caffeine, you should know how to measure the caffeine content in your cup before you gulp it down. So, let’s see how it is done!

How to measure caffeine content?

Measure the amount of dry coffee you add to your morning cup. Multiply the amount in grams by 0.008, and you will have a rough estimate of caffeine content. This calculation suggests that every 20gm of coffee contains about 160gm of caffeine.

However, there is more to measuring caffeine content in coffee and caffeinated drinks. So, hang in there!

Do caffeine testing strips work?

Do you know the decaf you ordered at your favourite coffee shop contains high levels of caffeine? Studies suggest that decaf beverages served in coffee shops often contain enough caffeine to affect caffeine-sensitive people.

The best way to measure the caffeine content in your drink is to use a strip. Caffeine testing strips are readily available in grocery stores and provide 98% accurate results.

Here’s how you can use a caffeine testing strip to measure the amount of caffeine in your drink:

  • Pour 6 oz of coffee into a cup and place a caffeine strip inside it.
  • Leave the strip for about 30 seconds.
  • Remove the strip and check the caffeine content.

If your drink contains more than 20 mg of caffeine, your strip will highlight the C line. And if the concentration of caffeine is below 20 mg, the strip will highlight the D line.

Important Note: Caffeine testing strips do not work on creamy coffee mixtures containing sugar, milk, or other ingredients. This strip gives accurate results only when tested on plain black coffee.

How much caffeine is in regular coffee?

Not everyone is a fan of black coffee, right? You may like to drink a mocha, cappuccino, or latte to start off your day. But since strips can only identify caffeine content in black coffee, how do you know how much caffeine is in your morning cup (if you don’t drink black coffee)?

While it’s difficult to determine the amount of caffeine in different types of coffee, I can give you a rough estimate of the caffeine content present in brewed coffee, espresso, instant coffee, and decaf.

Type of CoffeeQuantityCaffeine Content
EspressoOne shot — 50ml63mg
Brewed CoffeeOne cup — 80z70 – 140mg
Instant CoffeeOne cup — 8oz96mg
DecafOne cup — 8oz0 – 7mg

How much caffeine is too much?

While coffee is considered a healthy drink that helps with cognitive performance and prevents the risk of type 2 diabetes, you can still go wrong with it!

Over-consumption of caffeine can lead to diarrhea, headache, and heartburn. Doctors often advise people with high blood pressure and heart issues to refrain from consuming too much caffeine.

But when does caffeine starts disrupting your health and how much is too much?

Over-consumption means consuming more than 400mg of caffeine per day. If you consume more than the prescribed amount, it is advisable to cut it down.

For pregnant women and breastfeeding mothers, the safe dosage of caffeine is around 200mg per day.

Consuming too much caffeine can cause mild to severe side effects, including:

  • Heartburn
  • Nausea
  • Diarrhea
  • Frequent urination
  • Migraine
  • Chest pain

Related Content: Diarrhea from Coffee: Why It Happens and How to Fix It?

How do you know if you are caffeine sensitive?

There is no lab-certified way to identify caffeine sensitivity in people. However, people with caffeine sensitivity often develop symptoms like diarrhea and headaches—even after consuming coffee within the prescribed amount.

Most people with low caffeine tolerance experience these symptoms even after drinking caffeinated drinks like cola or tea.

A variety of factors are responsible for causing low caffeine tolerance including psychological issues, liver dysfunction, or genetics.

Important Note: Sensitivity to caffeine is not considered an allergy but a common immune dysfunction…

Do popular chains serve more caffeinated drinks?

If you are drinking your morning cup from a commercial brand, chances are you are consuming more caffeine. A single espresso shot from brands like Starbucks can contain 75 mg of caffeine, while your average home-brewed coffee contains 70mg of caffeine.

Additionally, most brands serve coffee in large cups holding up to 24 oz of drink, which is thrice more than the amount you consume in regular mugs.

Starbucks, Dunkin Donuts, and McDonald’s—all serve coffee with higher caffeine content. A small cup of coffee at Dunkin Donut can fill you in with a whopping 215 mg of caffeine! And a normal decaf at Starbucks contains up to 30 mg of caffeine.

See the table below to know how much caffeine commercial brands are serving per drink.

StarbucksDunkin DonutsMcDonald’s
Single shot espresso — 75mgSmall coffee — 215mgSmall coffee — 109mg
Grande — 330mgLarge coffee — 431mgLarge coffee — 180mg
Large espresso — 150 to 225mgEspresso — 75mgEspresso — 71mg
Decaf — 30mgDecaf — 53 to 129mgDecaf — 8 to 17mg

Related Content: Can you Get Decaf Iced Coffee at Starbucks


Measuring caffeine content is a straightforward thing when you are brewing your coffee at home. However, if you purchase from different brands, it’s hard to identify how much caffeine you are consuming in a day.

Symptoms like jitters and headaches after drinking coffee indicate low caffeine tolerance. People with caffeine sensitivity should brew their own coffee and use caffeine testing strips to check caffeine content before drinking.

Try to balance your caffeine intake to enjoy the health benefits of coffee. 

Mian Mohsin (MohsinZox)

About Author:

I'm Mian Mohsin the founder of the DeesCoffee. Here, I share step-by-step guides and explore different coffee products from my personal experience. Learn more...