Source-backed comparison
Red Bull vs Monster: Caffeine per Can and per 100 ml
Compare the manufacturer-listed caffeine in a UK 250 ml Red Bull and a UK 500 ml Monster Original Green, including serving and concentration differences.
| Measure | Red Bull Energy Drink | Monster Energy Original Green |
|---|---|---|
| Named serving | 250 ml can | 500 ml can |
| Market | UK | UK |
| Caffeine per serving | 80 mg | 160 mg |
| Caffeine per 100 ml | 32.0 mg | 32.0 mg |
| Value basis | Manufacturer listed | Manufacturer listed |
| Estimated after 5 hours | 40 mg | 80 mg |
| Absolute difference | 80 mg | 80 mg |
| Difference vs lower serving | 100.0% | 100.0% |
How to interpret the comparison
- A standard UK Red Bull contains 80 mg in 250 ml, while the named UK Monster can contains 160 mg in 500 ml.
- Both manufacturers list 32 mg per 100 ml for these products, so the full Monster can contains twice as much because its named serving is twice the volume.
- This compares the named Original products only. Other sizes, product lines and countries can use different formulations.
Guide updated 2026-09-24
Per can and per 100 ml answer different questions
The short answer
The named UK Original servings both correspond to 32 mg per 100 ml. The 500 ml Monster serving is twice the volume of the 250 ml Red Bull serving.
The equal-volume calculation
At 32 mg per 100 ml, a 250 ml portion is 80 mg by arithmetic. That explains the difference between the named cans without suggesting that one concentration is stronger. A portion calculation is not a claim that a particular alternative pack is sold.
Check variants separately
Sugarfree, Ultra and other ranges have their own records. Use the actual product and market, not the parent brand, before calculating a timeline. The comparison here does not rank nutrition, health effects or individual response.
Educational information, not medical advice. Published, calculated and approximate values have different limits. Check the current product label or recipe when an exact amount matters.
Calculated five-hour timeline
This table applies the same exponential half-life equation to both starting amounts. It does not show measured blood levels or predict which drink will affect a particular person more.
| Hours after serving | Red Bull Energy Drink | Monster Energy Original Green |
|---|---|---|
| 0 | 80 mg | 160 mg |
| 3 | 52.8 mg | 105.6 mg |
| 5 | 40 mg | 80 mg |
| 8 | 26.4 mg | 52.8 mg |
| 10 | 20 mg | 40 mg |
| 12 | 15.2 mg | 30.3 mg |
Sources
- Red Bull GB product informationUK product page for the standard 250 ml can.
- Monster Energy UK product informationUK Original Green product page.
Find lower-caffeine alternatives to Red Bull Energy Drink or compare drinks against a bedtime target.