Caffeine Intake Calculator
Track your daily caffeine in milligrams
Your Profile
Add Your Drinks
Total Caffeine Today
Your Daily Limit
399mg
Caffeine Remaining in Body
Based on ~5-hour half-life. Time since your last drink.
Caffeine Tips
How the Limit is Calculated
The FDA, EFSA, and most national health bodies agree on the following daily caffeine limits for healthy individuals:
⚠️ Values above are averages. Serving sizes, brewing method, and brand vary significantly. This tool is for guidance only, not medical advice.
Caffeine Intake Calculator — know your milligrams
About the Caffeine Intake Calculator
The caffeine intake calculator lets you log every caffeinated drink, snack, or supplement you've had today and instantly see your total in milligrams. Instead of guessing whether "three coffees" is too much, you get a precise figure and a comparison against the safe daily limit for your body weight and life stage.
Most online caffeine charts show a single serving at a time, which makes it hard to add up a real day. This tool builds a running cart of 21 common sources — brewed coffee, espresso, cold brew, tea, matcha, energy drinks, cola, dark chocolate, caffeine pills — each with its standard serving size and typical caffeine content based on USDA and manufacturer data.
The safe limit is personalised: a 400mg ceiling for standard adults (per the FDA and EFSA), 200mg for pregnant or breastfeeding women (per NHS and ACOG), and 100mg for teens. A weight-based cap (5.7mg/kg) is applied on top so smaller-framed adults get a lower recommendation. The calculator also estimates how much caffeine remains in your system 6 and 12 hours later, using caffeine's ~5-hour half-life — useful for judging whether afternoon coffee will hurt your sleep.
How to Use the Caffeine Intake Calculator
- Enter your body weight — type your weight and pick kg or lbs. This personalises your daily limit.
- Pick your status — standard adult, pregnant/breastfeeding, or teen. The safe limit updates automatically.
- Add each drink you've had — choose from the dropdown (grouped by coffee, tea, energy drinks, soda, and other) and tap the + Add button. The same drink can be added multiple times or adjusted with the quantity steppers.
- Read your total — the big orange card shows total milligrams and the equivalent in cups of brewed coffee. The progress bar shows how close you are to your daily limit with a colour-coded status badge.
- Check the sleep forecast — once you've added drinks, the panel shows how much caffeine will still be in your bloodstream after 6 and 12 hours. If the 12-hour value is above 50mg, expect disrupted sleep.
Common Use Cases
- • Improving sleep quality If you sleep poorly despite going to bed on time, caffeine is often the culprit. Log your daily drinks to see how much is still in your system at bedtime.
- • Pregnancy planning Safe caffeine during pregnancy is below 200mg per day. A large specialty coffee alone can exceed that — use the calculator to stay within guidelines.
- • Managing anxiety or heart palpitations If your doctor has asked you to reduce caffeine, this tool gives you a concrete milligram number to track rather than a vague "how many cups".
- • Pre-workout and fitness Many pre-workout supplements contain 150–300mg per scoop. Add a caffeine pill entry to account for them before your coffee pushes you over 400mg.
- • Withdrawal and tapering If you're cutting back, target a daily milligram reduction (e.g. 50mg less per week) instead of cup counting — the calculator makes this precise.
Frequently Asked Questions
How much caffeine is safe per day?
The FDA and EFSA recommend healthy adults stay under 400mg of caffeine per day — roughly four 8oz cups of brewed coffee. Pregnant and breastfeeding women should stay below 200mg, and teens under 100mg. Smaller adults may need less; this calculator personalises the limit by body weight.
How much caffeine is in a cup of coffee?
An 8oz cup of brewed drip coffee contains roughly 95mg of caffeine. A shot of espresso is 64mg. A 12oz latte or cappuccino (two shots) is about 128mg. Cold brew is much stronger — a typical 12oz serving delivers around 200mg. Specialty shop sizes are often 16oz or larger, so a "regular coffee" can easily exceed 200mg.
How long does caffeine stay in your system?
Caffeine has an average half-life of about 5 hours in healthy adults — meaning half is still active 5 hours after consumption, a quarter after 10 hours. A 200mg coffee at 3pm leaves roughly 50mg active at 11pm, enough to disrupt deep sleep for many people. Genetics (CYP1A2) and pregnancy can double or triple this half-life.
Is tea better than coffee for caffeine?
Tea generally delivers less caffeine per cup (20–50mg vs 95mg for coffee) and contains L-theanine, which smooths the stimulation. Matcha and yerba mate are exceptions and can match coffee's caffeine content. Green and white teas are the gentlest common options.
Do decaf drinks have any caffeine?
Yes — "decaf" coffee is not caffeine-free. A standard decaf cup still contains 2–15mg. Decaf tea typically has 5–10mg. Someone who has five decaf cups a day is still getting 10–75mg of caffeine.
What are the symptoms of too much caffeine?
Common symptoms of overconsumption include jitters, rapid heartbeat, anxiety, insomnia, digestive upset, headaches, and muscle tremors. These usually appear above 400–500mg in a single day for most adults, but sensitive people may feel them from much less.
Can caffeine affect blood pressure or heart rate?
Yes — caffeine causes a short-term rise in blood pressure (typically 5–10 mmHg) and can trigger palpitations in sensitive individuals. Regular consumers develop partial tolerance. If you have heart disease, arrhythmia, or uncontrolled hypertension, consult your doctor about caffeine limits.
Does the calculator store my data?
No — everything runs locally in your browser. Nothing is sent to a server, saved in a database, or shared. Refreshing the page clears your inputs.