Coffee, brewed vs Red Bull: caffeine compared
Coffee, brewed (8 oz) has 95 mg of caffeine, 15 mg more than Red Bull (8.4 oz, 80 mg) — 1.2× as much per serving. Per fluid ounce, Coffee, brewed is the stronger drink: 11.9 mg/oz versus 9.5 mg/oz.
| Coffee, brewed | Red Bull | |
|---|---|---|
| Serving | 8 oz | 8.4 oz |
| Caffeine per serving | 95 mg | 80 mg |
| Per fl oz | 11.9 mg | 9.5 mg |
| Share of 400 mg/day | 24% | 20% |
| Servings to reach 400 mg | 4.2 | 5.0 |
| Hours until under 50 mg | 4.6 h | 3.4 h |
| Last one for an 11 PM bedtime · standard (50 mg) | 6:22 PM | 7:37 PM |
| Last one for an 11 PM bedtime · sensitive (25 mg) | 1:22 PM | 2:37 PM |
| Share of the 200 mg pregnancy limit | 48% | 40% |
One serving of each, over 16 hours
Common questions
Which has more caffeine, Coffee, brewed or Red Bull?
Coffee, brewed (8 oz) has about 95 mg versus 80 mg in Red Bull (8.4 oz): 15 mg more, or 1.2× as much.
Which is stronger per ounce, Coffee, brewed or Red Bull?
Coffee, brewed: about 11.9 mg per fl oz versus 9.5 mg for Red Bull. Serving size decides the total you actually drink.
How many Red Bull servings equal one Coffee, brewed?
About 1.2 servings of Red Bull (8.4 oz) match the caffeine in one Coffee, brewed (8 oz).
When should I stop drinking Coffee, brewed or Red Bull before bed?
For an 11 PM bedtime with a 50 mg limit and a 5-hour half-life: last Coffee, brewed by 6:22 PM, last Red Bull by 7:37 PM. Half-life varies from about 1.5 to 9.5 hours between people.
Method
Caffeine per labeled serving, from the same drink table every calculator here uses (FDA/USDA reference amounts and manufacturer labels; see caffeine content of every drink). Brewed drinks vary batch to batch, so read these as typical values. Decay uses a 5-hour average half-life with a 45-minute absorption ramp; cutoff = bedtime − 5 h × log₂(dose ÷ limit). Percentages use the FDA's 400 mg/day figure for healthy adults and the 200 mg/day limit ACOG gives for pregnancy.
Source — Coffee, brewed: USDA FoodData Central (SR Legacy 171890), checked 2026-10-13. 40 mg per 100 g × 237 g (8 fl oz).
Source — Red Bull: Red Bull — caffeine per can, checked 2026-10-13.