Estimates only, not medical advice. If you are pregnant, have a health condition or take medication, ask your doctor.
Where the numbers come from
Most figures come from the Mayo Clinic and from lab tests of café drinks. A single espresso lands around 63 mg. An 8 oz cup of drip coffee holds about 96 mg. Some drinks have no measured figure, so their number is worked out from shot count. One lab study found café single shots between 33 and 82 mg.
What the guidance says
The FDA and EFSA both say up to 400 mg a day for healthy adults. Roughly two to three 12 oz cups. EFSA also says up to 200 mg at one time raises no safety concern. In pregnancy, EFSA and the NHS advise up to 200 mg a day. People differ in sensitivity, so read the limits as a guide.
Why the same drink varies
Caffeine depends on bean, roast, dose, grind and brew time. Robusta beans carry roughly 1.5 to 2 times the caffeine of arabica. In one study, the same café drink varied from 259 to 564 mg across six days. Milk adds none, so a latte has the caffeine of its shots. So the figure for your cup is an estimate.