how much caffeine is in  cup of coffee?
A 12-ounce cup of coffee that you brew at home contains about 100 to 160 milligrams of caffeine. Use a coffee maker with coffee pods and you're likely to get between 75 and 150 milligrams per cup. Instant coffee contains between 135 and 148 milligrams per cup. Purchase that cup at a coffeehouse and you'll get between 178 and 260 milligrams in a 12-ounce serving. A shot of espresso contains about 150 milligrams of caffeine. Any specialty drink, such as a mocha or latte, made with a single shot will thus also contain 150 milligrams. Frozen coffee drinks also contain significant amounts of caffeine -- between 140 and 260 milligrams per serving.