How much caffeine is in a Red Bull?
80 mg in the original 8.4 oz can, a little less than an 8 oz brewed coffee, which has about 95 mg. The bigger cans scale up, with 114 mg in the 12 oz, 151 mg in the 16 oz and 198 mg in the 20 oz, by Red Bull’s own numbers.
Red Bull is the can people picture when they say “energy drink”, and energy drinks have a reputation as rocket fuel. The small can is milder than a mug of coffee. Red Bull itself says its 8.4 oz can has “about the same amount as in a cup of home-brewed coffee”. By the ounce it’s actually weaker, about 9.5 mg an ounce against about 12 for brewed coffee.
We’d call the small can a mild afternoon drink and the 20 oz a morning one. Red Bull sells the same drink in four sizes, like small, medium, large and extra large at a coffee shop, and the caffeine follows the size. The 20 oz is two and a half small cans.
Every can, and how late it can be
| Can | Caffeine | Left at 11pm from a 3pm can | Latest for an 11pm bedtime |
|---|---|---|---|
| 8.4 oz | 80 mg | 29 mg | about 5:15pm |
| 12 oz | 114 mg | 42 mg | about 2:40pm |
| 16 oz | 151 mg | 55 mg | about 12:40pm |
| 20 oz | 198 mg | 72 mg | about 10:45am |
The latest times keep you under 40 mg when you fall asleep, the lower of our two bedtime lines, on the average half-life of 5 hours. A small can at 3pm leaves about 29 mg at 11pm, less than a can of Coke starts with.
Red Bull against the others
A 16 oz Red Bull (151 mg) and a 16 oz Monster (160 mg, by the label) are close to even. A 12 oz CELSIUS has 200 mg in a smaller can, more than a 20 oz Red Bull (caffeine in a CELSIUS). And a 16 oz brewed coffee, at about 190 mg, beats the 16 oz Red Bull by about 40 mg. The idea that energy drinks always have more caffeine than coffee is one of our myths.
Not for teens
Pediatricians advise against any energy drinks for children and teens, the small can included, according to the American Academy of Child and Adolescent Psychiatry’s 2026 sheet. For ages 12 to 18 they suggest at most 100 mg of caffeine a day from anything, and a 12 oz Red Bull is already over that (caffeine for teenagers).
Try your can
Pick your size in the cutoff clock below and slide the time to see what it leaves at your bedtime. One tap swaps it for something smaller and shows the hours that buys.
If the Red Bull is your afternoon pick-me-up, how to have more energy without caffeine has what to try first. In one small study, 10 minutes of easy stair walking made tired students feel more energetic than 50 mg of caffeine.
80 mg
Red Bull, 8.4 oz can. Red Bull: 80 mg in the 8.4 oz can. One at 3pm still leaves about 29 mg at an 11pm bedtime.
When should I stop?
When you fall asleep at 11:00pm
83 mgA measured cost
You'll fall asleep with about a cup of coffee in you.
- Brewed coffee, 8 oz95 mg
Brewed coffee, 16 oz190 mg
Your last drink, a 16 oz coffee at 3:00pm
- Under 40 mg at sleep
- by 8:10am
- Under 80 mg
- by 2:45pm
The full clock, with the band, 3am and the table by drink.
6 sources
- Red Bull, How much caffeine is in a can of Red Bull? checked 2026-11-14redbull.com
- USDA FoodData Central, SR Legacy: brewed coffee (171890), espresso (171891), brewed black tea (173227) and brewed green tea (171917)fdc.nal.usda.gov
- Monster Energy, 16 fl oz can, label photographed November 2025 (caffeine from all sources 160 mg per can), Open Food Facts 0070847811169, checked 2026-11-14world.openfoodfacts.org
- American Academy of Child and Adolescent Psychiatry, Facts for Families No. 131: Caffeine and Children, April 2026aacap.org
- Antonio J and others, Common questions and misconceptions about caffeine supplementation: what does the scientific evidence really show? Journal of the International Society of Sports Nutrition, 2024doi.org
- Randolph DD, O'Connor PJ, Stair walking is more energizing than low dose caffeine in sleep deprived young women, Physiology and Behavior, 2017doi.org
