Red Bull vs 5-hour Energy: caffeine compared
5-hour Energy (1.9 oz) has 200 mg of caffeine, 120 mg more than Red Bull (8.4 oz, 80 mg) — 2.5× as much per serving. Per fluid ounce, 5-hour Energy is the stronger drink: 105 mg/oz versus 9.5 mg/oz.
| Red Bull | 5-hour Energy | |
|---|---|---|
| Serving | 8.4 oz | 1.9 oz |
| Caffeine per serving | 80 mg | 200 mg |
| Per fl oz | 9.5 mg | 105 mg |
| Share of 400 mg/day | 20% | 50% |
| Servings to reach 400 mg | 5.0 | 2.0 |
| Hours until under 50 mg | 3.4 h | 10.0 h |
| Last one for an 11 PM bedtime · standard (50 mg) | 7:37 PM | 1:00 PM |
| Last one for an 11 PM bedtime · sensitive (25 mg) | 2:37 PM | 8:00 AM |
| Share of the 200 mg pregnancy limit | 40% | 100% |
One serving of each, over 16 hours
Common questions
Which has more caffeine, Red Bull or 5-hour Energy?
5-hour Energy (1.9 oz) has about 200 mg versus 80 mg in Red Bull (8.4 oz): 120 mg more, or 2.5× as much.
Which is stronger per ounce, Red Bull or 5-hour Energy?
5-hour Energy: about 105 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 5-hour Energy?
About 2.5 servings of Red Bull (8.4 oz) match the caffeine in one 5-hour Energy (1.9 oz).
When should I stop drinking Red Bull or 5-hour Energy 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 5-hour Energy by 1:00 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 — 5-hour Energy: CSPI caffeine chart (5-hour Energy Regular Strength, 1.9 oz), checked 2026-10-13.