Red Bull vs Monster Energy: caffeine compared
Monster Energy (16 oz) has 160 mg of caffeine, 46 mg more than Red Bull (12 oz, 114 mg) — 1.4× as much per serving. Per fluid ounce, Monster Energy is the stronger drink: 10.0 mg/oz versus 9.5 mg/oz.
| Red Bull | Monster Energy | |
|---|---|---|
| Serving | 12 oz | 16 oz |
| Caffeine per serving | 114 mg | 160 mg |
| Per fl oz | 9.5 mg | 10.0 mg |
| Share of 400 mg/day | 28% | 40% |
| Servings to reach 400 mg | 3.5 | 2.5 |
| Hours until under 50 mg | 5.9 h | 8.4 h |
| Last one for an 11 PM bedtime · standard (50 mg) | 5:03 PM | 2:37 PM |
| Last one for an 11 PM bedtime · sensitive (25 mg) | 12:03 PM | 9:37 AM |
| Share of the 200 mg pregnancy limit | 57% | 80% |
One serving of each, over 16 hours
Common questions
Which has more caffeine, Red Bull or Monster Energy?
Monster Energy (16 oz) has about 160 mg versus 114 mg in Red Bull (12 oz): 46 mg more, or 1.4× as much.
Which is stronger per ounce, Red Bull or Monster Energy?
Monster Energy: about 10.0 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 Monster Energy?
About 1.4 servings of Red Bull (12 oz) match the caffeine in one Monster Energy (16 oz).
When should I stop drinking Red Bull or Monster Energy before bed?
For an 11 PM bedtime with a 50 mg limit and a 5-hour half-life: last Red Bull by 5:03 PM, last Monster Energy by 2:37 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 — Red Bull: Red Bull — caffeine per can, checked 2026-10-13.
Source — Monster Energy: CSPI caffeine chart (Monster Energy Original, 16 oz), checked 2026-10-13.