The short answer
A standard 8 oz (240 ml) cup of brewed coffee contains about 95 mg of caffeine, according to USDA and FDA data — most cups fall in the 80–100 mg range. But that number shifts a lot by drink type, serving size, and how it's brewed. A double espresso, a large cold brew, and a mug of decaf can differ by 100 mg or more.
The figure people quote — "about 95 mg" — is specifically drip/filter coffee. Here's how the rest compare.
Caffeine by coffee drink
Typical caffeine per standard serving:
• Brewed / drip coffee (8 oz): ~95 mg (range 80–100).
• Espresso (1 shot, ~1 oz): ~63 mg. A double is ~125 mg.
• Latte or cappuccino: same as its shots — ~63 mg (one shot) or ~125 mg (two). The milk adds no caffeine.
• Cold brew (8 oz): ~150–240 mg — often the most caffeinated cup, because of its strong coffee-to-water ratio and long steep. See caffeine in espresso vs cold brew vs drip.
• Instant coffee (8 oz): ~60–80 mg.
• Decaf (8 oz): ~2–5 mg — not zero, but negligible.
Note the surprise: a single espresso (63 mg) has *less* caffeine than a full cup of drip (95 mg). Espresso just tastes stronger because it's concentrated.
What changes the caffeine number
Four things move it most:
• Serving size. A 16 oz coffee has roughly twice the caffeine of an 8 oz one. Café "cups" are often 12–20 oz, so a real-world coffee can hit 200–300 mg.
• Brew method. Longer contact between water and grounds extracts more caffeine — which is why cold brew and French press run high.
• Coffee-to-water ratio. More grounds per cup means more caffeine. Dial yours with the brew ratio calculator.
• Roast level — the myth. Dark and light roasts have nearly identical caffeine by weight. The common belief that dark roast is stronger isn't true; any difference is tiny.
How to track your daily caffeine
If you're watching your intake — for sleep, anxiety, or pregnancy — totals add up faster than people expect once you count size and refills. The caffeine intake calculator adds up your day by drink and serving, and the how much caffeine is too much guide covers safe limits.
To see how long that caffeine sticks around, read how long caffeine lasts.