Dr Pepper (12 oz Can) Caffeine Half-Life & Bedtime Decay
A 12 fl oz can of Dr Pepper contains 41mg of caffeine, slightly higher than Coca-Cola and Pepsi.
Interactive Stack Calculator for Dr Pepper (12 oz Can)
We've preloaded Dr Pepper (12 oz Can) (41mg) 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.
Caffeine Sensitivity
Not sure? If an afternoon coffee keeps you up at night, pick Slow.
Pick your next drink
Last safe 41 mg drink
Calculated so that under 50 mg of caffeine is still circulating at bedtime, counting today's drinks.
Today's drinks alone leave about 6 mg at bedtime.
Solid: caffeine from today's drinks.
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.
Download on theApp StoreEmbed this calculator on your site
Are you a blogger or health coach? Copy the code below to add this tool to your website and help your readers protect their sleep.
<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>
Dr Pepper (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 | 32 mg | 25 mg | 19 mg | 15 mg | 12 mg | 9 mg | 6 mg | ✓ Sleep Safe |
| 12:00 PM (Noon) | 32 mg | 25 mg | 19 mg | 15 mg | 12 mg | 9 mg | 10 mg | ✓ Sleep Safe |
| 02:00 PM | 32 mg | 25 mg | 19 mg | 15 mg | 12 mg | 9 mg | 13 mg | ✓ Sleep Safe |
| 04:00 PM | 32 mg | 25 mg | 19 mg | 15 mg | 12 mg | 9 mg | 17 mg | ✓ Sleep Safe |
Cutoff Recommendation: Finish by 5:30 PM for an 11:00 PM sleep schedule.
Values are calculated using the standard exponential decay model: mg_remaining = initial_mg * 0.5^(hours / half_life).
How Your Genetics (CYP1A2) Impact Dr Pepper (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 41mg vary drastically:
Residual after 8 hours: 10 mg. You clear caffeine rapidly and rarely experience insomnia from lunch beverages.
Residual after 8 hours: 15 mg. Standard biological decay rate representing ~50% of the population.
Residual after 8 hours: 19 mg. CYP1A2*1F carriers. Any caffeine consumed past noon will disrupt sleep architecture.
Frequently asked questions
How long does Dr Pepper caffeine stay in your system?
With 41mg, after 5.5 hours only 20.5mg remains, falling well under any sleep-disruptive biological threshold.