A standard 8-ounce cup of brewed coffee has about 80 to 100 milligrams of caffeine, while a single shot of espresso has around 63 milligrams. The exact amount depends on the bean, roast, grind, brew method and serving size, so two cups are rarely identical. As a rule of thumb, drip coffee has the most caffeine per serving because the serving is larger.

Quick Answer

An 8-ounce cup of brewed coffee has roughly 80 to 100mg of caffeine; an espresso shot about 63mg. Larger servings and darker brews vary. Most healthy adults can have up to about 400mg a day.

Short Answer

Brewed coffee has about 80 to 100mg of caffeine per 8-ounce cup; espresso about 63mg per shot. The amount varies with bean, roast and serving size, but drip coffee usually delivers the most per cup because the cup is bigger.

Caffeine by Coffee Type

Drink Serving Approx caffeine
Brewed (drip) coffee 8 oz 80–100mg
Espresso 1 shot (1 oz) ~63mg
Latte / cappuccino 1 shot base ~63mg (1 shot)
Cold brew 8 oz (diluted) ~100–200mg
Instant coffee 8 oz ~60–80mg
Decaf 8 oz ~2–5mg

Key Takeaway: Serving size matters more than people expect. An espresso has less caffeine than a mug of drip coffee, even though it tastes much stronger.

What Affects Caffeine Content

  • Serving size: bigger cups have more caffeine.
  • Bean type: robusta has roughly double the caffeine of arabica.
  • Roast: by scoop, lighter roasts have slightly more; by weight the difference is small.
  • Brew method: longer contact time, like cold brew, can extract more.
  • Grind and dose: more coffee means more caffeine.

Does Espresso Have More Caffeine?

Per ounce, espresso is more concentrated, but a single shot is only about an ounce, so it has less total caffeine than a full mug of drip coffee. A double shot gets closer to a small cup. The strong taste of espresso is about concentration, not total caffeine.

How Much Is Safe?

Most healthy adults can consume up to about 400mg of caffeine a day, roughly four cups of brewed coffee, according to general guidance. Sensitivity varies, and pregnant people and those with certain conditions should consume less. Listen to your body and limit late-day coffee for better sleep.

FAQ

How much caffeine is in a cup of coffee?

An 8-ounce cup of brewed coffee has about 80 to 100mg of caffeine. Larger mugs and stronger brews have more, and the bean and roast also affect the amount.

Does espresso have more caffeine than coffee?

Per ounce, yes, but a single espresso shot has less total caffeine than a full mug of drip coffee because the serving is much smaller.

How much caffeine is too much?

Most healthy adults can have up to about 400mg a day. More than that can cause jitters and poor sleep, and some people are more sensitive.

Bottom Line

A cup of brewed coffee has about 80 to 100mg of caffeine and an espresso shot about 63mg, varying with bean, roast and size. Keep within about 400mg a day for most adults. To brew it well, see our best coffee makers and how much coffee per cup guides.

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