Exactly How Much And How Often You Should Be Drinking Coffee

Two cups or six? A certain amount of coffee is good for you, but too much of a good thing could undo the benefits.

Exactly How Much And How Often You Should Be Drinking Coffee
[Image: Flickr user Thomas Angermann]

If you treat your daily caffeine jolt as though it were a sacred ritual, you’re not alone.


According to a Zagat survey earlier this year, 87% of Americans consume at least one cup of coffee a day. Fifty-five percent even admitted to being addicted to their daily cup.

While caffeine in moderate doses can increase mental alertness, fight off headaches, and even help prevent diseases such as Alzheimer’s, type 2 diabetes and certain cancers, worshiping your neighborhood barista can have some serious negative side effects. You might want to read before downing your sixth cup of coffee.

Caffeine is the most widely used psychoactive stimulant, targeting the central nervous system and heightening your brain’s feeling of alertness. According to the FDA, 400 mg per day of caffeine (that’s about four cups of coffee) is a safe amount of caffeine for healthy adults. But too much caffeine–500 to 600 mg–can be dangerous, causing restlessness, tremors, irritability, insomnia and stomach upset.

The problem is, most of us don’t just consume caffeine in coffee, but in chocolate and soda as well. Caffeine is now being added to gum and other previously caffeine-free treats such as jelly beans, meaning it’s not difficult to hit your daily maximum even without making a double Starbucks run.

For many of us, it may be hard to imagine how to get through our day without our daily cup of coffee. While caffeine’s stimulant effects will vary from person to person depending on a number of factors including body mass index, medication use, and existing health conditions such as anxiety disorders; knowing how much caffeine you consume daily can be the key to optimizing its positive benefits, heightening your concentration and mental alertness when you need it and decreasing it when it’s time to rest.

How much caffeine is in my coffee?

While four cups of coffee may seem high, keep in mind most coffee shops serve beverages larger than 8 oz. A Starbucks Grande (16 oz.) contains 330 mg of caffeine while a 20 oz. Venti contains 415 mg–just above your daily maximum.


The most recent annual National Coffee Association of USA’s National Coffee Drinking Trends showed the popularity of specialty coffees and espresso-based drinks such as cappuccinos and lattes is on the rise, jumping from 13% last year to 18%. But that single 1 oz. shot of espresso alone contains 64 mg of caffeine.

Moderate caffeine intake may be key to optimizing its benefits

Although many of us enjoy a large caffeine jolt to jumpstart the morning, A landmark 2004 study by researchers at Harvard Medical School on the best caffeinating strategies revealed small, frequent doses of caffeine–about 2 oz. (or a quarter cup of coffee) every hour–is the best strategy to stay alert and awake throughout the entire day.

Caffeine reaches its peak level in the blood stream within 30 to 60 minutes of consumption and can remain elevated for three to five hours before you begin to crash. Optimizing caffeine’s stimulant effects all day long may mean swapping your ginormous coffee-addict mug for a teacup size cup several times a day.

Track your intake

If you’re concerned about your daily intake, you may want to consider downloading caffeine tracking apps to help you determine the optimal time for a caffeine jolt. Caffeine Zone 2 (free for iOS), developed by the ACS Lab at Penn State University, allows users to note the amount of caffeine consumed and tracks how long the stimulant will remain elevated in your bloodstream. A graph shows how your caffeine intake will affect your alertness level and your sleep.

If you punch in another cup while you’re still “in the zone” (or at your optimal level of awareness)–which the app determines as having between 200 and 400 mg of caffeine in your bloodstream–it will give you a warning that the drink won’t do you any good. Jawbone’s Up Coffee (iOS) or Caffeine Tracker (for Android) provide similar tracking services.


About the author

Lisa Evans is a freelance writer from Toronto who covers topics related to mental and physical health. She strives to help readers make small changes to their daily habits that have a profound and lasting impact on their productivity and overall job satisfaction.