Caffeine Intake Calculator – How Much Caffeine Are You Having?
Add up coffee, tea, soda, and energy drinks to see your total caffeine and how it compares to common daily limits.
How this calculator helps
Caffeine adds up quickly across coffee, tea, soda, and energy drinks, and it is easy to lose track of the running total across a busy day. This calculator combines common serving sizes into a single estimate so you can see how close you are to a recommended daily limit before adding another cup.
Formula: Total caffeine (mg) = (coffee cups × 95) + (tea cups × 47) + (soda cans × 35) + (energy drinks × 80).
Bedtime estimate: For a separate timing check, the calculator models only your most recent serving: estimated caffeine remaining = serving milligrams × 0.5^(hours until bed ÷ half-life). The default five-hour half-life is a rough population-level estimate, not a personal measurement.
Assumptions: Caffeine content varies by brand, brew strength, and serving size, so these are average values for an 8 oz coffee cup, 8 oz tea cup, 12 oz soda can, and 8 oz energy drink serving.
Worked example: Two cups of coffee, one cup of tea, and no soda or energy drinks totals about 237 mg, roughly 59% of the general 400 mg adult guideline. A 95 mg coffee five hours before bed with a five-hour half-life leaves an estimated 48 mg from that serving.
- Coffee, tea, soda, energy drinks: Enter the number of standard servings you typically have in a day.
- Daily limit: Choose the guideline that best matches your situation.
- Bedtime fields: Enter the caffeine in your latest serving, time until bed, and an optional half-life assumption.
- Result: Daily total and limit comparison, plus a separate estimate for the latest serving at bedtime.
What the result means
The total is a practical estimate rather than a lab-verified measurement, since actual caffeine content depends on brew strength, bean or leaf type, and serving size. The bedtime figure answers a narrower question: how much caffeine from one selected recent serving may remain after the hours you enter. Earlier drinks are intentionally excluded from that figure, so it is not a full-body caffeine total.
Caffeine half-life varies with individual biology, medications, pregnancy, and other factors. Adjusting the half-life lets you explore scenarios, but it cannot establish how your body processes caffeine or predict whether you will sleep well.
Caffeine sensitivity varies significantly between individuals due to genetics, tolerance, medication, and pregnancy, which is why this calculator offers several limit guidelines instead of a single number. If you regularly find yourself well above your chosen limit, consider gradually reducing intake rather than stopping abruptly, since sudden withdrawal can cause headaches and fatigue.
Caffeine limits referenced here reflect general guidance from the U.S. Food and Drug Administration and health organizations such as the American College of Obstetricians and Gynecologists, which suggest keeping intake under about 400 mg per day for most healthy adults and under about 200 mg per day during pregnancy.
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Frequently asked questions
- Does the bedtime estimate include all drinks today? No. It models the most recent serving only. Add the earlier drinks to the daily total, but do not interpret the bedtime figure as a cumulative estimate.
- Are these caffeine values exact? No, actual caffeine content varies by brand, brew strength, and serving size, so treat this as a practical estimate.
- What if I go over my daily limit occasionally? Occasional excess is common, but frequent high intake can affect sleep, anxiety, and heart rate, so consider gradually cutting back if it happens often.
- Why is the pregnancy limit lower? Health guidelines recommend keeping caffeine under about 200 mg per day during pregnancy due to slower caffeine clearance and potential effects on the baby.
- Does decaf coffee count? Decaf still contains a small amount of caffeine, roughly 2 to 5 mg per cup, which is not included in this estimate.
Creator & reviewers
Creator persona
- Quinn ParkerWellness & nutrition estimates
Reviewer personas
- Casey RowanUnits, conversions & measurement
- Sage MitchellClarity & usability review