Red Bull vs Coca-Cola: caffeine compared
Red Bull (8.4 oz) has 80 mg of caffeine, 46 mg more than Coca-Cola (12 oz, 34 mg) — 2.4× as much per serving. Per fluid ounce, Red Bull is the stronger drink: 9.5 mg/oz versus 2.8 mg/oz.
| Red Bull | Coca-Cola | |
|---|---|---|
| Serving | 8.4 oz | 12 oz |
| Caffeine per serving | 80 mg | 34 mg |
| Per fl oz | 9.5 mg | 2.8 mg |
| Share of 400 mg/day | 20% | 8% |
| Servings to reach 400 mg | 5.0 | 11.8 |
| Hours until under 50 mg | 3.4 h | already under |
| Last one for an 11 PM bedtime · standard (50 mg) | 7:37 PM | 11:00 PM |
| Last one for an 11 PM bedtime · sensitive (25 mg) | 2:37 PM | 8:47 PM |
| Share of the 200 mg pregnancy limit | 40% | 17% |
One serving of each, over 16 hours
Common questions
Which has more caffeine, Red Bull or Coca-Cola?
Red Bull (8.4 oz) has about 80 mg versus 34 mg in Coca-Cola (12 oz): 46 mg more, or 2.4× as much.
Which is stronger per ounce, Red Bull or Coca-Cola?
Red Bull: about 9.5 mg per fl oz versus 2.8 mg for Coca-Cola. Serving size decides the total you actually drink.
How many Coca-Cola servings equal one Red Bull?
About 2.4 servings of Coca-Cola (12 oz) match the caffeine in one Red Bull (8.4 oz).
When should I stop drinking Red Bull or Coca-Cola before bed?
For an 11 PM bedtime with a 50 mg limit and a 5-hour half-life: last Red Bull by 7:37 PM, last Coca-Cola by 11:00 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 — Red Bull: Red Bull — caffeine per can, checked 2026-10-13.
Source — Coca-Cola: Coca-Cola — What is caffeine? (FAQ), checked 2026-10-13.