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Which Energy Drinks Have the Most Caffeine?
The energy drinks with the most caffeine per can are Bang, Reign, Monster Killer Brew and Java Monster 300, each with 300 mg. Celsius Essentials follows at 270 mg, then Rockstar Pure Zero and Rockstar Punched at 240 mg. At the other end, a regular 8.4 oz Red Bull has 80 mg.
But “the most caffeine” depends on how you measure it. A 2 oz energy shot can have more caffeine per ounce than any can, and a big 24 oz can has more in total even if each sip is milder. So below you’ll find two rankings, per can and per ounce, plus what those numbers mean for your daily limit.
Energy Drinks Ranked by Caffeine per Can
| Rank | Energy drink | Size | Caffeine per can | Caffeine per oz |
|---|---|---|---|---|
| 1 | Bang | 16 oz | 300 mg | 18.8 mg |
| 1 | Reign Total Body Fuel | 16 oz | 300 mg | 18.8 mg |
| 1 | Monster Killer Brew (incl. Loca Moca) | 15 oz | 300 mg | 20.0 mg |
| 1 | Java Monster 300 | 15 oz | 300 mg | 20.0 mg |
| 5 | Celsius Essentials | 16 oz | 270 mg | 16.9 mg |
| 6 | Mega Monster | 24 oz | 240 mg | 10.0 mg |
| 6 | Rockstar Pure Zero | 16 oz | 240 mg | 15.0 mg |
| 6 | Rockstar Punched | 16 oz | 240 mg | 15.0 mg |
| 9 | Celsius | 12 oz | 200 mg | 16.7 mg |
| 9 | Alani Nu | 12 oz | 200 mg | 16.7 mg |
| 9 | Ghost Energy | 16 oz | 200 mg | 12.5 mg |
| 9 | C4 Performance Energy | 16 oz | 200 mg | 12.5 mg |
| 9 | Java Monster | 15 oz | 200 mg | 13.3 mg |
| 14 | Monster Energy Original | 16 oz | 160 mg | 10.0 mg |
| 14 | Rockstar Original | 16 oz | 160 mg | 10.0 mg |
| 14 | Rockstar Recovery | 16 oz | 160 mg | 10.0 mg |
| 17 | Monster Ultra (most flavors) | 16 oz | 150 mg | 9.4 mg |
| 18 | Red Bull | 8.4 oz | 80 mg | 9.5 mg |
Sources: Caffeine Informer (Monster range including Killer Brew, Java Monster 300 and Mega Monster), Caffeine Informer (Rockstar Pure Zero), Caffeine Informer (Rockstar Punched), Caffeine Informer (Rockstar Recovery), H-E-B label (Celsius) and Barista Life (Bang, Reign, Celsius Essentials, Alani Nu, Ghost, C4, Rockstar Original, Red Bull). Caffeine per ounce is our calculation. Flavors and formulas change, so the can’s label is the final word.
Energy Drinks Ranked by Caffeine per Ounce
Per ounce shows how “strong” each sip is. That’s why a small can can hit harder than you’d expect.
| Energy drink | Caffeine per oz |
|---|---|
| 5-hour Energy (1.93 oz shot, 200 mg) | about 103.6 mg |
| Monster Killer Brew / Java Monster 300 | 20.0 mg |
| Bang / Reign | 18.8 mg |
| Celsius Essentials | 16.9 mg |
| Celsius / Alani Nu | 16.7 mg |
| Rockstar Pure Zero / Punched | 15.0 mg |
| Monster Original / Rockstar Original | 10.0 mg |
| Red Bull | 9.5 mg |
| Monster Ultra | 9.4 mg |
5-hour Energy figure from Barista Life; per-ounce values are our calculation from the figures above.
Energy shots are in a league of their own: one 2 oz bottle of regular 5-hour Energy has as much caffeine as a 12 oz Celsius, packed into a few sips. Among cans, Killer Brew is the most concentrated.
How Much Caffeine Is Too Much?
The FDA cites 400 mg a day as an amount not generally linked to dangerous or negative effects for healthy adults (FDA). Here’s how fast the strongest drinks use that up:
| Drink | Caffeine | Share of the 400 mg daily guideline |
|---|---|---|
| Bang, Reign, Killer Brew | 300 mg | 75% |
| Celsius Essentials | 270 mg | 68% |
| Rockstar Pure Zero / Punched | 240 mg | 60% |
| Celsius | 200 mg | 50% |
| Monster Original | 160 mg | 40% |
| Monster Ultra | 150 mg | 38% |
| Red Bull | 80 mg | 20% |
In other words, one 300 mg can plus a cup of coffee can put you over the daily guideline. Two 300 mg cans in a day means 600 mg, 50% over.
The FDA also notes that energy drinks on the market range from about 54 to 328 mg of caffeine per 16 oz (FDA), so the gap between the mildest and strongest cans is huge. Always check the label.
Signs you’ve had too much
According to the FDA, too much caffeine can cause a faster heartbeat, palpitations, higher blood pressure, trouble sleeping, anxiety, jitteriness, an upset stomach, nausea and headaches. If you feel any of these, stop drinking caffeine for the day and drink water. Get medical help for chest pain, a racing heart that won’t settle, or fainting.
The Strongest Drinks Explained
Bang and Reign (300 mg)
Both are 16 oz performance-style energy drinks with 300 mg of caffeine per can (Barista Life). They’re aimed at gym-goers who want a pre-workout-style kick. One can is three-quarters of your daily caffeine.
Monster Killer Brew and Java Monster 300 (300 mg)
These are coffee-based Monsters with 300 mg in a 15 oz can (Caffeine Informer), the most concentrated cans on this list. Killer Brew Loca Moca tastes like an iced mocha, which makes it easy to forget how strong it is. Treat one can like two regular Monsters. See Killer Brew Loca Moca. Our full guide to how much caffeine is in Monster covers every line.
Celsius Essentials (270 mg) and Celsius (200 mg)
Celsius is strong for its size: 200 mg in a 12 oz can, and 270 mg in the 16 oz Essentials line. Both are sugar-free. Read more in what is Celsius drink? and is Celsius bad for you?
Rockstar Pure Zero and Rockstar Punched (240 mg)
Rockstar’s zero-sugar Pure Zero line and the Punched line both have 240 mg per 16 oz can (Caffeine Informer; Caffeine Informer), noticeably more than Rockstar Original’s 160 mg. Popular flavors include Pure Zero Silver Ice, Pure Zero Fruit Punch and Punched Fruit Punch.
Lower-Caffeine Energy Drinks
If you want energy without the extreme dose, these moderate options are better everyday choices:
- Red Bull (8.4 oz): 80 mg. The mildest classic can.
- Monster Ultra: 140 to 155 mg depending on flavor, zero sugar. Ultra Red is one of the lower ones at 140 mg; see every flavor in our Monster Ultra caffeine guide.
- Monster Lo-Carb: 140 mg. Shop Lo-Carb.
- Rockstar Recovery: 160 mg and non-carbonated. Shop Recovery Lemonade.
For a full ranking based on sugar and calories as well as caffeine, see our guide to the healthiest energy drinks.
Why Do Some Energy Drinks Have So Much Caffeine?
Caffeine is the ingredient that does almost all of the work in an energy drink. Brands compete on “strength,” and 300 mg cans are marketed to gym-goers as a pre-workout alternative. Some drinks also add guarana, a plant seed that naturally contains caffeine; a University of California, Davis fact sheet notes guarana contains roughly 40 mg of caffeine per gram (UC Davis). Most labels now list total caffeine from all sources, which is the number to check. Learn what everything else on the label does in what’s in energy drinks.
FAQs
Which energy drink has the most caffeine?
Among popular cans, Bang, Reign, Monster Killer Brew and Java Monster 300 tie at 300 mg. Per ounce, energy shots like 5-hour Energy are stronger still.
Is 300 mg of caffeine a lot?
Yes. It’s 75% of the FDA’s 400 mg daily guideline for healthy adults in a single can. It’s more than most people need at one time.
Which has more caffeine, Monster or Red Bull?
A 16 oz Monster has 160 mg, while an 8.4 oz Red Bull has 80 mg. Per ounce they’re similar (about 10 mg vs 9.5 mg); Monster’s can is simply twice the size.
Does Celsius have more caffeine than Monster?
Yes. A 12 oz Celsius has 200 mg, more than the 160 mg in a bigger 16 oz Monster.
What’s the strongest Monster?
Monster Killer Brew and Java Monster 300 have 300 mg in a 15 oz can. Regular Monster has 160 mg.
Is it safe to drink two 300 mg energy drinks a day?
No. Two cans is 600 mg, well above the FDA’s 400 mg guideline for healthy adults.
What energy drink has the least caffeine?
Of the drinks listed here, Red Bull has the least, at 80 mg per 8.4 oz can.
The Bottom Line
The highest-caffeine energy drinks are Bang, Reign, Monster Killer Brew and Java Monster 300 at 300 mg per can, followed by Celsius Essentials (270 mg) and Rockstar Pure Zero and Punched (240 mg). Any of these can use up most of your daily caffeine in one go. For everyday drinking, a 140 to 160 mg can is a safer middle ground.
Shop energy drinks by the case at DrinkWorlds → From moderate Monster Ultra to strong Rockstar Pure Zero, with free US shipping on orders over $35.
