How Much Caffeine in Coffee: From 40mg to Safe Intake Level of 400mg

Most Americans enjoy a good cup of coffee.

Statistics compiled by the National Coffee Association showed that 62% of adults in the U.S. drink at least one cup of coffee each day.

People adore their favorite beverage for the taste and, yes, because of the pleasant buzz it can provide. But often, people forget that that sensation comes thanks to a substance that’s essentially a drug: caffeine.

So, the question is: how much caffeine in coffee? How many cups can you safely have each day? First, let’s see an overview table:

There’s a really good summary on YouTube by James Hoffmann. It’s a thorough video you should check out:

Let’s learn more about how much caffeine is in a cup of coffee!

1. How Much Caffeine in Coffee Can You Safely Drink?

We’ve all been there.

You drink one cup to give you an extra boost to finish a project. When that starts to fade, you turn to another cup to keep your attention focused. Fast forward to five cups later and your heart is pumping and your stomach is starting to cramp.

Where did you cross the line? At what point did you pass the safe caffeine level?

These are important questions for any regular coffee drinker. A little caffeine can provide a nice pick-me-up in the middle of a tough day. But too much can lead to serious physiological reactions.

You need to stay within the recommended intake level. Medical authorities have placed the top level of safe intake at 400 milligrams (mg)

Of course, your exact caffeine tolerance limit depends on other factors too (like your weight). But 400 milligrams is a “hard limit” nobody should go over.

How Much Caffeine In Coffee Pouring Coffee

So what does that limit look like in caffeinated beverages. The highest caffeine limit corresponds to what you’d find in each of the following:

  • 4 cups of coffee (an average cup)
  • 10 cans of soda
  • 13 cups of green tea
  • 2 “energy shot” drinks
  • 8 cups of black tea

The exact caffeine intake in a single cup of coffee will depend on the particular situation. As a general rule of thumb, you can consider the amount in an average cup as somewhere around 100 mg. Serving size is an important concept to keep in mind as we move through this discussion.

Here, we’ll assume that an average cup of coffee equates to eight fluid ounces (oz). 

The caffeine amount in coffee is about twice the amount you’d find in a cup of green tea, which typically carries a dose between 30 and 50 mg. On the other end of the spectrum, your coffee contains about half the caffeine in an energy shot, like 5-Hour Energy.

So if you stay within safe ranges coffee intake, you’re fine.

In fact, in that case you stand to gain from the potential benefits of coffee! In reasonable amounts, coffee doesn’t just give you that extra energy boost. It can also bolster your health in a slew of other ways:

  • Decreased risk of Parkinson’s
  • Decreased risk of stroke
  • Decreased risk of Alzheimer’s disease
  • Decreased risk of heart failure
  • Improved glucose processing
  • Improved liver function

But if you start to suffer negative consequences, it might be time to look for options with less caffeine.

2. What Are the Effects of too much caffeine?

Caffeine operates in the body by affecting the adenosine receptors.

The impact on the central nervous system offers some of its benefits. This explains some of the protection observed for conditions like Alzheimer’s and Parkinson’s.

If you overdo your coffee intake you can experience certain side effects.

Here are some of the major symptoms that can manifest if you push past the safe limit of caffeine dosage.

  • anxiety/nervousness
  • headaches
  • rapid heartbeat
  • stomach pains
  • nausea
  • insomnia
  • high blood pressure

Keep in mind that caffeine can become addictive. Over time you can develop a tolerance. This condition means that similar doses start to have less of an effect the more you drink them.

Your body can also become dependent on caffeine. If you cut down your intake, you could face withdrawal symptoms.

How Much Caffeine In Coffee Cup Of Coffee

What should you do if you are over-caffeinated? It can take more than 9 hours for the caffeine to work its way through your system.

Here are a few steps you can take:

  1. Start drinking water. This will help you dilute the caffeine in your system. (It will also prevent you from becoming dehydrated and suffering a headache later.)
  2. Eat certain foods. You’re looking for items with magnesium and potassium. Bananas represent a good choice in this case.
  3. Work out some of those extra jitters with exercise. This should help speed your metabolism and work some of the caffeine out of your system faster.

Now let’s take a detailed look at different types of coffee, brews and brands to see how much caffeine they contain.

3. What is the amount of caffeine content in popular coffee? (Different Brews, Chains, Brands)

In this section, we’ll focus on a few common types of coffee.

We’ll give their typical caffeine levels and the max number of cups you should consume in a day. To compute this figure, we’ll use the 400 mg threshold as our limit.

Also, we’ll look at the number of cups of each one that will deliver that “perfect buzz.” According to experts, most people need between 100 and 200 mg of caffeine to reach that peak level. For our purposes, we’ll split the difference and target 150 mg as the ideal total. 

The right amount of caffeine varies from person to person. It has a lot to do with your body type and physiological chemistry. 

For most of these, we’ll present the calculations for an 8 oz serving. We break this rule for espresso, which typically comes in a smaller shot.

Brewed Coffee

This is the basic coffee we’ve been talking about (and the one you’d use when brewing pour-over coffee).

How Much Caffeine In Coffee Delicious Hot Coffee On Light Background

The caffeine total depends on many factors, but we’ll use 100 mg as a baseline.

  • Caffeine Content: 100 mg
  • Max recommended cups per day: 4
  • Perfect buzz cups: 2


As we noted, you have to treat shots of espresso differently than other types of coffee. The serving size isn’t equivalent. Espresso shots (one ounce) each contain about 63 mg of caffeine

How Much Caffeine In Coffee Fresh Coffee Pouring From The Spout Of A Portafilter, Espresso Machine

A double shot of espresso is usually enough to reach the perfect buzz. If double shots don’t quite work for you, you can probably push it to three. Though, at that point, you put down more than 180 mg of caffeine.

  • Caffeine Content: 63 mg
  • Max recommended cups per day: 6
  • Perfect buzz cups: 2-3


Cold-brew coffee has a similar caffeine count to a regular cup brewed with hot water. The total varies, of course, based on the type and other factors. For a 12-oz cup, you’ll find somewhere in the range of 150-250 mg.

How Much Caffeine In Coffee Pouring Cold Brew Iced Coffee

So far, we’ve used an 8 oz serving size for regular coffee. Using this measure, the figures equate to a range of about 100 to 170 mg per serving.

  • Caffeine Content: 100 mg
  • Max recommended cups per day: 4
  • Perfect buzz cups: 2

Instant Coffee

The caffeine levels drop for instant coffee. For an 8 oz cup, you’ll find 57 mg.

How Much Caffeine In Coffee Glass Coffee Cup And Spoon With Instant Granulated Coffee

That’s roughly 60% of the dose present in a fresh-brewed serving.

  • Caffeine Content: 57 mg
  • Max recommended cups per day: 7
  • Perfect buzz cups: 3

4. How Much Caffeine Is in a cup of Coffee from Chains?

It gets difficult to compare brands because they have such a wide variety of products. Head to Starbucks and you can enjoy a Caramel Macchiato, a Caffè Americano, a simple brewed coffee, or any number of other types of drinks.

To get a base, we’re going to look at the simplest brewed products. These will give an apples-to-apples comparison.


A short serving of dark roast at Starbucks equates to about 8 oz.

How Much Caffeine In Coffee Starbucks Cup

It carries a caffeine total of 130 mg, higher than average for a brewed cup of coffee.

  • Caffeine Content: 130 mg
  • Max recommended cups per day: 3
  • Perfect buzz cups: 1-2

Dunkin Donuts

Starbucks and Dunkin Donuts are about even when it comes to caffeine.

How Much Caffeine In Coffee Dunkin Donuts

Potentially, you could get a slightly bigger buzz from Starbucks, but the difference is probably too small to notice.

  • Caffeine Content: 120 mg
  • Max recommended cups per day: 3
  • Perfect buzz cups: 1-2


The caffeine count at McDonald’s is below average.

How Much Caffeine In Coffee Cup Of Mccafe

At just over 9 mg per ounce, an 8 oz serving will net you about 72 mg.

  • Caffeine Content: 72 mg
  • Max recommended cups per day: 5
  • Perfect buzz cups: 2-3

5. An Emerging Conclusion: drinking coffee for the benefits of coffee vs decaf coffee

Need that first cup of coffee to get up in the morning? You have caffeine to thank for those added bursts of alertness.

Caffeine creates a series of useful reactions in the body. However, don’t push your intake too far.

You now know how much caffeine is in a cup of coffee. Be aware of how small changes can alter the caffeine content and get the most benefit you can from your favorite drink.

And if you really need that extra cup, maybe consider having a decaf coffee 😉

Frequently Asked Questions

What Factors Affect Caffeine Content in Coffee?

How Much Caffeine In Coffee

Every cup of coffee varies, not just in taste but also in its chemical composition, influencing flavor and caffeine content. These differences are shaped by several key factors:
☕ Type of coffee bean
☕ Roasting Method
☕ Serving Size
☕ Brewing method

And what do other people think about caffeine intake?

Here are some opinions from Reddit and its biggest coffee subreddit!

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