How Daily Caffeine Intake Is Calculated
The FDA recommends healthy adults consume no more than 400 mg of caffeine per day. That is roughly four 8-oz cups of brewed coffee. Pregnant women should stay under 200 mg. Amounts vary by brew method, serving size, and brand, so treat these values as general estimates.
Each drink type has a standard caffeine value: brewed coffee ~95 mg, espresso shot ~63 mg, energy drink ~80 mg, green tea ~28 mg, black tea ~47 mg, and cola ~34 mg per can. Regular consumption above 600 mg daily is linked to side effects including insomnia and elevated heart rate.
Caffeine Content by Drink
| Drink | Serving | Caffeine |
|---|---|---|
| Drip coffee | 8 oz | ~95 mg |
| Espresso | 1 shot | ~63 mg |
| Energy drink | 8 oz can | ~80 mg |
| Green tea | 8 oz | ~28 mg |
| Black tea | 8 oz | ~47 mg |
Frequently Asked Questions
Yes, decaf still contains 2–15 mg of caffeine per cup. While much lower than regular coffee, it is not entirely caffeine-free.
Yes, regular caffeine users develop tolerance over time, requiring more to achieve the same effect. Periodic breaks from caffeine can help reset tolerance levels.