How much caffeine is in Rockstar Energy?

A 16 fl oz can of Rockstar Energy has 161 mg of caffeine.

That's about one and a half cups of brewed coffee, and 40% of the 400 mg a day the FDA cites for most healthy adults.

Source: rockstarenergy.com · checked 10 Nov 2026

Rockstar Blackberry, Lemonade and Lime Freeze list the same 160 mg per 16 fl oz can.

When did you have it?

Had at 3 pm, about 57 mg is still in you at an 11 pm bedtime. That might affect your sleep.

Bedtime

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Sizes

Size	Volume	Caffeine	mg per fl oz
16 fl oz can shown above	16 fl oz (473 ml)	161 mg	10
12 fl oz (half a 24 oz can)	12 fl oz (355 ml)	120 mg	10

Source: rockstarenergy.com · checked 10 Nov 2026

Latest time to drink it

For an 11 pm bedtime, most people should finish a 16 fl oz can of Rockstar Energy by about 2:05 pm. The table works it out for other bedtimes and for how sensitive you are: it is the latest time to start one so that the caffeine left stays under the line all night.

Bedtime	Very sensitive under 25 mg	Average under 50 mg	Not very sensitive under 100 mg
9 pm	7:05 am	12:05 pm	5:05 pm
10 pm	8:05 am	1:05 pm	6:05 pm
11 pm	9:05 am	2:05 pm	7:05 pm
Midnight	10:05 am	3:05 pm	8:05 pm
1 am	11:05 am	4:05 pm	9:05 pm

For a 16 fl oz can of Rockstar Energy, average clearance (half-life 5 h), 8 hours of sleep. "Any time" means even one at bedtime stays under the line.

How long it lasts

The caffeine from a 16 fl oz can of Rockstar Energy peaks in your blood about 75 minutes after you start it, at roughly 137 mg. Half of it is gone in about 5 hours for an average adult; that ranges from roughly 3 to 7 hours, and longer in pregnancy or with some medicines.

Time after	3 hours	6 hours	9 hours	12 hours
Still in you	113 mg	75 mg	49 mg	32 mg

So one had at 3 pm leaves about 57 mg at 11 pm. How long caffeine lasts explains the curve.

How it compares

Rockstar Energy is stronger than 43% of the 41 energy drinks we track, by caffeine per serving.

Per fluid ounce (10 mg) it is stronger than 38% of them.

To reach 400 mg in a day you would need about 2½ of these.

Less caffeine

IRN-BRU Energy 160 mg, 500 ml can
Monster Energy 160 mg, 16 fl oz can
Monster Nitro Super Dry 160 mg, 16 fl oz can

More caffeine

Bloom Sparkling Energy 180 mg, 12 fl oz can
Java Monster Mean Bean 188 to 200 mg, 15 fl oz can
3D Energy 200 mg, 16 fl oz can

Same caffeine: Full Throttle.

FAQ

Is Rockstar Energy high in caffeine?

Yes. A 16 fl oz can of Rockstar Energy has 161 mg, which is 1.7 times an 8 fl oz cup of brewed coffee (95 mg).

How much caffeine is in 12 fl oz of Rockstar Energy?

A 12 fl oz (half a 24 oz can) of Rockstar Energy has 120 mg of caffeine, 41 mg less than a 16 fl oz can of Rockstar Energy.

Can I drink Rockstar Energy at night?

Not if you want to sleep well. Had at 7 pm, it leaves about 98 mg in an average adult at an 11 pm bedtime, above the 50 mg most people sleep fine with. The latest time for an 11 pm bedtime is about 2:05 pm.

How long does the caffeine in Rockstar Energy last?

It peaks about 75 minutes after you start it. Of the 161 mg, about 75 mg is still in you 6 hours later and 32 mg after 12 hours, for an average adult with a 5-hour half-life.

Does Rockstar Energy have more caffeine than a cup of coffee?

Yes. A 16 fl oz can of Rockstar Energy has 161 mg; an 8 fl oz cup of coffee has 95 mg.

Method and limits

The caffeine figure comes from rockstarenergy.com and the other sources listed above; recipes, brewing and batches vary, so a real serving can differ. The curves use a standard one-compartment model with an average 5-hour half-life and a sleep-friendly line of 50 mg; your own body may clear caffeine faster or slower. How it works has the details.

These are estimates for information, not medical advice.

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