Calculator
Enter your details to estimate a practical caffeine dose range.
Example data table
These examples assume normal sensitivity and moderate intake.
| Bodyweight (kg) | Goal | Range (mg/kg) | Session range (mg) |
|---|---|---|---|
| 60 | Workout performance | 3–6 | 162–324 |
| 75 | Focus and alertness | 1–3 | 68–203 |
| 90 | Fat-loss support | 2–4 | 162–324 |
| 80 | Workout performance | 3–6 | 216–432* |
*Upper values may be capped by your daily limit setting.
Formula used
The calculator starts with a goal-based range in mg/kg, then scales by bodyweight:
dose(mg) = weight(kg) × target(mg/kg) × sensitivityFactor × habitFactor
- Goal ranges: performance 3–6, alertness 1–3, fat-loss 2–4 mg/kg.
- Sensitivity: high 0.75, normal 1.00, low 1.15.
- Habit: none 1.00, moderate 0.90, high 0.80.
- Safety: session range is capped by the chosen daily limit.
How to use this calculator
- Enter your bodyweight and select your goal.
- Pick sensitivity and habitual intake that match you.
- Choose a timing style and a daily limit mode.
- Select a caffeine source to estimate servings.
- Click Calculate, then export CSV or PDF.
FAQs
1) What is a common caffeine dose for training?
Many athletes use 3–6 mg per kg bodyweight for performance. Start at the low end, especially if you feel jittery or rarely use caffeine.
2) When should I take caffeine before a workout?
A typical window is 30–60 minutes before training. If you split dosing, the second dose can be 60–120 minutes later, if needed.
3) How does tolerance change my results?
Frequent intake can reduce perceived effects. This calculator lowers the range when you select higher habitual use, to reduce overshooting your needs.
4) Is 400 mg per day always safe?
It is a common adult upper limit, but sensitivity varies. Some people need less, and certain conditions or medications can make caffeine riskier.
5) Can caffeine hurt sleep even if I feel fine?
Yes. Caffeine can reduce sleep quality without obvious jitters. Use the “avoid after” hour to set a cutoff and protect recovery.
6) How accurate are caffeine amounts in coffee and tea?
They vary by bean, brew, size, and brand. Use label values when available. For precision, choose tablets or products with listed caffeine content.
7) Should beginners use split dosing?
Split dosing can reduce side effects and lets you stop early if you feel overstimulated. Beginners should still start near the low end.
8) Who should avoid using this calculator without advice?
People who are pregnant, have heart rhythm issues, uncontrolled blood pressure, severe anxiety, or who use stimulant medications should consult a clinician first.