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.

Most healthy adults can stay at or under 400 mg caffeine per day, while pregnancy caps are often set under 200 mg and teens do better with far less.

Most adults can handle up to 400 mg of caffeine per day, with lower caps for pregnancy, teens, and people who feel side effects sooner.

Most healthy adults do well at 400 mg a day or less, while pregnancy calls for staying under 200 mg.

A typical 8-oz cup of brewed green tea lands around 20–45 mg of caffeine, with prep choices often shifting the number more than the label.

Most 15-year-olds do best staying at or under 100 mg of caffeine per day, with less if sleep, stress, or heart symptoms show up.

Many pediatric groups cap teens at 100 mg of caffeine per day, and plenty of 13-year-olds feel better staying below that.