Daily How Much

For healthy adults, 400 mg of caffeine per day is the upper intake many health agencies cite as safe.

Most pregnancy guidelines cap caffeine at 200 mg a day, which is roughly one 12-oz brewed coffee.

Many clinicians advise zero caffeine under age 12; for teens, a common ceiling is 100 mg per day, with weight-based limits near 2.5–3 mg/kg.

Most healthy adults do best at 400 mg of caffeine a day or less, with lower limits during pregnancy and for people who feel it sooner.

A typical 8-ounce cup of black tea lands around 40–70 mg of caffeine, with the final amount driven by leaf dose, brew time, and water heat.

Most breastfeeding moms can keep caffeine at 200–300 mg a day without issues for many babies, with lower targets for newborns.

Many pediatric sources suggest keeping caffeine under 100 mg per day at age 12, and skipping energy drinks.

A 12-oz can of Coca-Cola has 34 mg of caffeine, while a 12-oz can of Diet Coke has 46 mg.

Matcha often runs near 20–45 mg of caffeine per gram of powder, so a bowl made with 2 g commonly lands near 40–90 mg.

A 12-oz can of Diet Coke has about 46 mg of caffeine; bottle and fountain pours can land higher or lower.