How much caffeine is in Monster Ultra?
of caffeine
Source: public manufacturer data and USDA FoodData Central. Values are estimates, not exact or medical measurements.
- 150 mg of caffeine per 473 ml (16 fl oz) serving (31.7 mg per 100 ml).
- About 1.6 cups of brewed coffee, and 38% of the FDA's 400 mg daily limit for healthy adults.
- After 6 hours roughly 72 mg is still in your system; after 12 hours about 35 mg.
- To stay under the 100 mg many people notice at bedtime, finish it about 3.3 h before sleep.
Monster Ultra delivers about 150 mg of caffeine per 473 ml (16 fl oz) serving, the equivalent of roughly 1.6 cups of brewed coffee (a 240 ml cup is about 96 mg). That is about 54 mg more caffeine than a standard cup of coffee.
At 31.7 mg per 100 ml, Monster Ultra is moderately concentrated by concentration — the fair way to compare it against drinks of a different size.
How long Monster Ultra stays in your system
Caffeine leaves the body through first-order elimination with a population-average half-life of about 5.7 hours. Starting from 150 mg, roughly 104 mg is left after 3 hours, about 72 mg after 6 hours, and around 35 mg after 12 hours. Your personal rate varies — smoking speeds it up, pregnancy and some medications slow it down — which is why the calculator below lets you set your own half-life and bedtime.
Monster Ultra and your daily limit
For most healthy adults the FDA points to about 400 mg of caffeine a day as an amount not generally linked to negative effects. One serving of Monster Ultra is 38% of that ceiling. Pregnant people are usually advised to stay under about 200 mg a day, and the American Academy of Pediatrics discourages caffeine for children and adolescents. This is general guidance, not medical advice. The easiest way to stay under your own limit is to log every drink — CoffeeLog adds up your real daily total automatically.
How long it stays in your system
Starting from one serving, here is roughly how much caffeine is left as the hours pass (population-average half-life of 5.7 hours).
| Time | Caffeine left | % left |
|---|---|---|
| At serving | 150 mg | 100% |
| After 1 h | 133 mg | 89% |
| After 3 h | 104 mg | 69% |
| After 6 h | 72 mg | 48% |
| After 9 h | 50 mg | 33% |
| After 12 h | 35 mg | 23% |
Your personal caffeine curve
Estimates for general information, not medical advice.
How it compares
| Drink | Serving | Caffeine |
|---|---|---|
| Monster Ultra | 473 ml | 150 mg |
| Bang | 473 ml | 300 mg |
| Reign | 473 ml | 300 mg |
| Celsius | 355 ml | 200 mg |
| Prime Energy | 355 ml | 200 mg |
| 5-Hour Energy | 57 ml | 200 mg |
| Monster Energy | 473 ml | 160 mg |
Frequently asked questions
How much caffeine is in Monster Ultra?
Monster Ultra contains about 150 mg of caffeine per 473 ml (16 fl oz) serving (31.7 mg per 100 ml). Values are public-source estimates, not exact measurements.
Is 150 mg of caffeine a lot?
It is about 1.6 cups of brewed coffee. The FDA considers up to 400 mg per day safe for most healthy adults, so this is a moderate single dose.
How long does the caffeine in Monster Ultra stay in your system?
Caffeine has a half-life of about 5.7 hours, so roughly 104 mg of the original 150 mg remains after 3 hours and about 35 mg after 12 hours. The calculator above shows your personal curve.
Will Monster Ultra keep you awake?
It can if you have it late. From 150 mg it takes roughly 3.3 hours to fall below the 100 mg level many people notice at bedtime. Finish it well before sleep, or use the cutoff above.
Track this automatically with CoffeeLog
Log any drink in one tap, watch caffeine fade in real time on your home screen, and get a nudge before it touches your sleep — the same engine that powers this page.
Related
TrackCaffeine provides general reference information about caffeine. It is not medical advice. Caffeine values are public-source estimates, not exact measurements.