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How much caffeine is in a cup of coffee? That’s like asking how much sugar is in a cookie. It depends on the type of cookie, how it’s made, and how big it is. Caffeine quantities vary wildly in coffee — in ways you might not realize. Many other drinks pack quite a buzz, too, as do some painkillers and other drugs, and anything containing chocolate.

So is caffeine even safe? Yes, up to around 400 milligrams (mg) a day for most people, according to the Food and Drug Administration. As a stimulant, it perks us up and enhances cognitive abilities. Coffee, along with its caffeine, contains other health-boosting chemicals and compounds, such that coffee drinking is strongly linked to better heart health, lower overall disease risk, and longer life. Same for tea, too. (Not true for soda.)

Some people, however, are more sensitive to caffeine than others, so if it makes you jittery, causes headaches or upsets your stomach, your “safe” threshold might be lower, or coffee simply might not be for you. And even serious coffee lovers should be aware of some important cautions, which I’ve included at the bottom of this article.

Caffeine comparisons

Here are caffeine quantities in common drinks, treats and drugs, according to the Center for Science in the Public Interest:

Coffee: The amount of caffeine in coffee varies based on how it’s roasted and other factors. Dark roasts have less caffeine than lighter roasts. Decaf is very low in caffeine, but it’s not caffeine-free.

An 8-ounce cup of coffee — a standard good-sized cup, should you still drink from one of those — can have anywhere from about 75 to 155 mg of caffeine. Folgers Classic Roast has about 95 mg per cup.

It can get confusing when you start comparing a standard cup to what we actually consume. A Starbucks “tall,” for example, which is essentially the company’s “small,” is 12 ounces. Here, then, are examples of caffeine in some popular 16-ounce servings, what Starbucks calls a “grande,” or what you can think of as two good-sized “cups” of coffee:

Tea: Most teas have about half the caffeine of coffee. Caffeine in a typical 8-ounce cup of tea ranges from 20 to 75 mg, so two cups (16 ounces) would amount to 40 to 150 mg.

Soda: Caffeine in a 12-ounce can of a typical popular cola or other caffeinated soda ranges from 20 to 70 mg, so for comparison, that’d be 27 to 93 mg in a 16-ounce serving.

Energy drinks: You might think these are off the scale, but most of them are similar to coffee. Most of the popular energy drinks range from 160 to 300 mg of caffeine per 16-ounce serving. Some have less.

Chocolate: The darker the chocolate, the higher the caffeine level (and the better it is for you, given other healthy compounds) so these are but two examples: One bar of Hershey’s Special Dark Chocolate — about 1.4 ounces, or 4 squares of a larger Lindt bar — has just 25 mg of caffeine, much less than a regular cup of regular coffee. Similarly modest amounts are present in a ⅔-cup serving of coffee-flavored ice creams and yogurts.

Medications: Caffeine is found in many painkillers. As just one example, Exedrin Migraine and Exedrin Tension Headache pack 65 mg of caffeine per capsule or caplet. If caffeine gives you headaches, well, ahem. Similar caffeine concentrations are found in Pamprin Max Pain + Energy and Midol Complete. About half as much is put into Bayer Back & Body Extra Strength.

Cautions to consider

Caffeine is a drug. Caffeine is natural. Both statements are true, and both drugs and natural substances can have side effects. Things you should know:

• Caffeine can raise blood pressure if you’re used to it, but habitual coffee drinkers don’t seem to be affected.
• Pregnant women are advised against consuming caffeine because it can cause low birth weight and raise the risk of miscarriages and birth defects.
• Caffeine is bad for kids, expert says, not because it stunts growth (it does not) but because it’s too strong a stimulant to introduce into a developing brain.
• Since it takes 4 to 6 hours to metabolize half of any caffeine you consume, the FDA says, it’s wise to avoid the stimulant from late afternoon onward.
• Ingesting loads of caffeine quickly, such as 1,200 milligrams all at once, can be toxic and even deadly, though caffeine deaths are rare.
• If you stop drinking coffee or other caffeinated products, you might experience headaches or sleepiness or get really cranky.

Also note that many weight-loss pills and potions contain caffeine, a ploy to give you, if nothing else, a temporary brain boost. If you think you need weight-loss drugs, see a doctor first. Much science finds that for most people, the better approach is to improve diet and get physically active. And then, what the heck, enjoy some coffee.

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