The average cup of coffee contains about 100 milligrams of coffee. An espresso often contains as little as 50 milligrams per shot and a cup of drip coffee can easily contain 200 milligrams of caffeine. That's a lot of variation!
Without a lab test or some guidelines, determining the caffeine levels of coffee and espresso drinks can be very tricky, and keeping your caffeine consumption below the recommended 300 milligrams per day can be even harder.
Or above 300, if that's what you're into. I don't especially recommend it, but drinking too much caffeine seems to be a popular activity for many these days.
Here's a handy list of caffeine levels in different coffee drinks. And here's a list of Starbucks coffee caffeine levels. Both great general references. However, they don't include everything, and some of the caffeine counts are estimates.
Why are caffeine levels estimated rather than exact? There are many factors that influence the caffeine levels in different coffee drinks, such as espresso, French press coffee and drip brewed coffee.
Whether you're looking for less caffeine or more, this guide will help you make more informed decisions about which coffee drinks you consume and how much caffeine they contain.
Caffeine Levels of Coffee Roasts
Many people believe that darker coffee roasts have more caffeine because they have a stronger flavor.
However, darker roasts generally have lower caffeine levels than lighter roasts. This is because the prolonged heat of heavier roasting breaks down the caffeine molecule, or as some people like to put it, roasting "burns off the caffeine".
Cool tidbit: Not sure about your coffee's roast? Just look at the color.
A lighter color means a lighter roast and more caffeine.
Caffeine Levels of Ground Coffee Beans
Different levels of coffee grinding are used for different brewing methods. For example, espresso and Turkish coffee require much finer coffee grind levels than drip brewed coffee.
Assuming that the brewing method is the same, the finer the coffee grind, the higher the coffee's caffeine level.
Caffeine in Coffee Bean Varietals
Like different tea varietals, different coffee varieties and cultivars have naturally varying levels of caffeine.
Robusta coffee beans (the type used in many low-grade coffees and instant coffees) have about twice as much caffeine as Arabica coffee beans (which is a softer, sweeter coffee mean that makes up 70 percent of the coffee beans on the market). Not sure which kind you're drinking? If it's an instant coffee, it's probably the higher-caffeine Robusta coffee bean. If it's from a coffee shop, a decent restaurant, a drip coffee maker, ground beans or whole beans, it's probably from lower-caffeine Arabica beans.
Cool tidbit: A naturally low-caffeine coffee bean (not decaf coffee) called Excelsa is sometimes blended with Arabica to create a lower caffeine coffee.
Caffeine Levels of Coffee Brewing Methods
Different coffee brewing methods require different brewing times. The longer you brew the coffee, the higher the level of caffeine it will have. For example, French press coffee that is left sitting for a longer amount of time before the plunger is depressed will have a higher caffeine level. So will drip-brewed coffee from a coffee machine (which is often left to brew for around five minutes). And lungos (larger, slower extractions of espresso) will have a higher caffeine level than ristrettos (smaller, faster extractions of espresso).
Similarly, if you brew your coffee with more ground beans per measurement water, there will be more caffeine in the brew. Most coffee recipes call for about 30 grams coffee per 12 to 16 ounces water. Using more than that will also increase the caffeine level in your coffee, and many people accidentally use more because they use a measuring spoon (or the 'eyeball method', if that can be called a method!) rather than a scale when making coffee.
Caffeine Levels in Pre-made Coffees
According to Thrillist, the Center for Science in the Public Interest and EnergyFiend.com, caffeine levels in fast food / coffee shop coffees varies wildly. A cup of coffee from McDonalds contains about half as much caffeine as the same serving size from Starbucks, and a cup from Caribou Coffee falls right betwixt the two.
Five Tips: What Can You Do About It?
- Read up on caffeine levels in popular US coffee drinks.
- Is your favorite coffee not listed? Some chain coffee retailers will provide caffeine counts on request. Ask and see if they can tell you.
- Note that many coffeehouse drinks contain more milk and flavorings than coffee and that means less coffee. Other stuff means less caffeine per serving.
- Brew your own coffee instead. One lab test compared the caffeine levels in Starbucks' Breakfast Blend Coffee from one Starbucks outlet, six days in a row. The caffeine levels per 16-ounce ("Grande") cup ranged from 299.5 mg (add a nibble of chocolate and you're reached the recommended daily limit) to a whopping 564.4 mg (practically double the daily limit). This has to do with variations in the beans, sure, but it probably has more to do with variations in the brewing. Yikes!
- When in doubt order a small!
So What Is the Coffee With the Most Caffeine?
If you look at all these factors together, the highest caffeine coffee would be a light roast, finely ground (as in, Turkish ground or espresso ground) Robusta coffee that has been brewed with a drip filter coffee maker or a French press for five minutes or more. Using more than the usual 30 grams coffee per 12 to 16 ounces water will also increase the caffeine level in your coffee.
Which Kind of Espresso Has the Most Caffeine?
Ditto everything above, except make it into a lungo using 7 to 8 grams (relatively coarsely ground) coffee grinds instead of brewing in a French press / drip coffee maker.
Which Coffee Has the Least Caffeine?
If you look at all the factors above, you'll find that dark roast, coarsely ground Arabica coffee beans that are brewed with a quicker brewing method (such as a pour-through drip filter) will have the least caffeine. Be sure to measure your grinds with a scale (not with a spoon, and definitely not with your eyes!) to make sure you're only using 30 grams per 12 to 16 ounces water (approximately two reasonable servings, or one big ol' Starbucks Grande or Tall). For a super-low caffeine coffee, use a decaf coffee* or a blend with Excelsa beans.
* Despite popular belief to the contrary, decaf is NOT caffeine free. A 16-ounce decaf coffee from Starbucks still contains about 12.5 mg caffeine, while a Starbucks decaf espresso has a bigger range--3 to 15.8 mg per serving.
Reminder for ordering coffee drinks: fancier coffee drinks (ones with milk and other additives) often contain less caffeine per serving. A small has far less caffeine than a large!
Which Kind of Espresso Has the Least Caffeine?
Seven grams of dark roast, relatively coarsely ground Robusta beans pulled as a single ristretto shot has less caffeine than other espresso shots. For a super-low caffeine ristretto, use a decaf coffee or a blend with Excelsa beans.
Cool tidbit: Although people tend to think of espresso as super-high in caffeine, one shot of espresso is generally lower in caffeine than a cup of coffee. It may be more concentrated than a cup of Joe, but an espresso is actually lower in caffeine. But beware! Many coffee shops sell 'double shots' as their standard size.
How Can I Cut Down on Caffeine and Stay Below 300 mg a Day?
Caffeine overdose and caffeine sensitivity are both seriously unpleasant, and too much caffeine can be dangerous for your health. If you want to cut down on your buzz or stay within a healthy limit, here are some great ways to do it.
- Order small. Brew small. Make and buy less coffee. Don't make more coffee than you WANT to drink. Never order a large when you can order something smaller.
- Remember that caffeine isn't just in coffee! There's also caffeine in tea, chocolate, cola and other substances, such as aspirin. If you consume those substances, too, look into cutting down on them as well.
- Follow these caffeine lowering tips. They'll help a lot!