How much caffeine is in a Coke?
A 12 oz can of Coca-Cola has about 34 mg of caffeine. See Coke, Diet Coke, and Coke Zero by size, and how it compares to coffee.
A 12 oz can of Coca-Cola has about 34 mg of caffeine, roughly a third of a cup of coffee. Diet Coke actually has more than regular, and Coke Zero is about the same as regular.
| Drink | Size | Caffeine |
|---|---|---|
| Coca-Cola | 12 oz can | 34 mg |
| Coca-Cola | 20 oz bottle | 57 mg |
| Diet Coke | 12 oz can | 46 mg |
| Coke Zero | 12 oz can | 34 mg |
Coke is relatively low in caffeine, but a couple of cans plus coffee still adds up, and the sugar and afternoon timing matter for sleep. Add it all up with the free Caffeine Calculator.
Written by Mike Zagare · Published
Mike Zagare is the founder of Knuckle. He tapered off a 500 to 600mg-a-day habit and built Knuckle from that protocol.
Common questions
Does Diet Coke have more caffeine than regular Coke?
Yes, slightly: about 46 mg per 12 oz versus 34 mg in regular Coke.
Does Coke Zero have caffeine?
Yes, about 34 mg per 12 oz, the same as regular Coca-Cola.
How does Coke compare to coffee?
A 12 oz Coke (34 mg) has roughly a third of the caffeine of an 8 oz brewed coffee (~95 mg).
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