Last updated: September 24, 2026
Planning tool, not medical advice
CaffCutoff provides general educational estimates for caffeine timing. It does not provide medical advice, diagnosis, treatment, or an assessment of whether a caffeine dose is safe for you. Do not use the calculator as a substitute for advice from a qualified healthcare professional.
Model limitations
The calculator defaults to a five-hour half-life model for an average adult, with optional fast and slow presets covering roughly four to seven hours. Actual caffeine metabolism can differ substantially due to genetics, age, pregnancy, smoking, liver health, medications, hormonal contraceptives, and other factors, so no preset is a measurement of you. The model does not account for absorption time, tolerance, sleep debt, or interactions between caffeine and other substances.
The 25 mg bedtime target
The 25 mg value is a simple planning target used to make cutoff estimates understandable. It is not a clinical threshold, a guarantee of restful sleep, or proof that a lower amount will be safe or symptom-free. Some people may experience sleep disruption or other effects at lower levels.
Drink amounts can vary
Preset caffeine amounts are common reference values only. Actual content varies by brand, serving size, preparation method, and batch. Use the product label or reliable manufacturer information whenever available.
Personal health decisions
Consult a healthcare professional if you are pregnant or breastfeeding, take medication, have a heart or liver condition, experience anxiety or sleep problems, or have concerns about caffeine use. If you develop severe or urgent symptoms, contact local emergency services or an appropriate poison-control service rather than relying on this website.
No guarantee
Estimates may be incomplete, inaccurate, or unsuitable for your circumstances. CaffCutoff does not guarantee sleep quality, alertness, performance, safety, or any health outcome. The caffeine persona is a playful summary and has no medical meaning.
Questions
Questions about this disclaimer can be sent to [email protected].