Soda · 54 mg Caffeine

Mountain Dew (12 oz Can) Caffeine Half-Life & Bedtime Decay

Mountain Dew has 54mg of caffeine in a 12 fl oz can, making it the most caffeinated mass-market non-energy soda in North America.

Total Caffeine54 mg

Serving Size12 fl oz can (355ml)

Average Half-Life5.5 Hours

Sleep-Safe Goal< 50 mg by Bed

Interactive Stack Calculator for Mountain Dew (12 oz Can)

We've preloaded Mountain Dew (12 oz Can) (54mg) below. Adjust your planned bedtime or add other drinks to see your exact curve.

Caffeine Half-Life & Cutoff Calculator

Caffeine's half-life ranges from about 4 to 7 hours depending on how fast you metabolise it. Add what you've already drunk today to find the last time your next drink still leaves under 50 mg in your system at bedtime.

Target Bedtime

Next Drink (mg)

Caffeine Sensitivity

Not sure? If an afternoon coffee keeps you up at night, pick Slow.

Drinks so far today

Earlier caffeine is still in your system and pulls your cutoff earlier.

Drink 1 (mg)

Time

Pick your next drink

Last safe 54 mg drink

8:59 PM

Calculated so that under 50 mg of caffeine is still circulating at bedtime, counting today's drinks.

Today's drinks alone leave about 8 mg at bedtime.

7:30 AMBed · 11:00 PM

Solid: caffeine from today's drinks. Dashed: with one more drink at your cutoff, landing on the 50 mg line at bedtime.

Stop guessing your cutoff.

Here you type your drinks in. ARC does the same math from every drink you log in one tap, moves your last safe coffee the moment you log a cup, shows it as a live countdown, and tells you plainly when no cup fits any more.

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<iframe src="https://arcapp.sbs/tools/caffeine-calculator" width="100%" height="600px" frameborder="0"></iframe>
<p>Caffeine calculator by <a href="https://arcapp.sbs/tools/caffeine-calculator">ARC</a></p>

Mountain Dew (12 oz Can) Hour-by-Hour Caffeine Decay Table

Pharmacokinetic Decay (5.5h Half-Life)

Exact milligrams of caffeine remaining in the bloodstream at 2-hour intervals if consumed at various times of day, based on an average human caffeine half-life of 5.5 hours. Target is less than 50mg active at 11:00 PM bedtime.

Intake Time	+2 hrs	+4 hrs	+6 hrs	+8 hrs	+10 hrs	+12 hrs	At 11 PM Bed	Status
08:00 AM	42 mg	33 mg	25 mg	20 mg	15 mg	12 mg	8 mg	✓ Sleep Safe
12:00 PM (Noon)	42 mg	33 mg	25 mg	20 mg	15 mg	12 mg	14 mg	✓ Sleep Safe
02:00 PM	42 mg	33 mg	25 mg	20 mg	15 mg	12 mg	17 mg	✓ Sleep Safe
04:00 PM	42 mg	33 mg	25 mg	20 mg	15 mg	12 mg	22 mg	✓ Sleep Safe

Cutoff Recommendation: Finish by 5:00 PM for an 11:00 PM bedtime.

Values are calculated using the standard exponential decay model: mg_remaining = initial_mg * 0.5^(hours / half_life).

How Your Genetics (CYP1A2) Impact Mountain Dew (12 oz Can) Clearance

Over 95% of caffeine metabolism takes place in your liver via the cytochrome P450 enzyme CYP1A2. Depending on whether you carry the fast or slow metabolizing gene variant, clearance times for 54mg vary drastically:

Fast Metabolizer

4.0 Hours

Residual after 8 hours: 14 mg. You clear caffeine rapidly and rarely experience insomnia from lunch beverages.

Average Metabolizer

5.5 Hours

Residual after 8 hours: 20 mg. Standard biological decay rate representing ~50% of the population.

Slow Metabolizer

7.0+ Hours

Residual after 8 hours: 24 mg. CYP1A2*1F carriers. Any caffeine consumed past noon will disrupt sleep architecture.

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