Caffeine Safe Limit Calculator
The 400 mg/day adult ceiling is a population guideline. Use your weight to estimate a more personal upper bound.
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The 400 mg/day adult ceiling is a population guideline. Use your weight to estimate a more personal upper bound.
How to use Caffeine Safe Limit Calculator
- Open the toolNo signup and nothing to install; it works as soon as the page loads.
- Set “Weight (kg)”
- Set “Sensitivity”
- Read the resultChange any input and the result is recalculated immediately.
Worked example with the defaults
- DAILY CAFFEINE LIMIT · Roughly 5.5 mg per kg of body weight (max 400 mg)
- 385 mg
Nothing you enter leaves your device
All of the work happens inside your browser. Whatever you type is never packaged up and sent to a server, and no request this page makes carries it.
That makes it safe for contract amounts, personal details and internal documents you would rather not hand to a third party — close the tab and it is gone.
What this tool does not do
Caffeine Safe Limit Calculator only does what a browser can do on its own — it talks to no backend service. So it keeps no history for you and syncs nothing across devices; if you need a record, copy or download the result.
It is also not a substitute for professional judgement. For legal, medical or tax decisions, treat the output as a starting point rather than a final answer.
Frequently Asked Questions
- Is 400 mg too much for me?
- If you feel jittery, get palpitations or disrupted sleep on 2 cups of coffee, you are probably in the low-sensitivity band and should keep it lower.