Health
Caffeine Intake Calculator
Track daily caffeine intake vs the 400 mg FDA guideline.
Inputs
Caffeine Intake Calculator
Result
Total caffeine today
190 mg
- % of 400 mg FDA guideline
- 0%
- Status
- Within guideline
- Est. in body at bedtime
- 69 mg
How it's calculated
Remaining = total × 0.5^(hours / 5.5) (half-life ≈ 5.5 h)
Common questions
Is 400 mg safe for everyone?
No — pregnant people, those with heart conditions, or those sensitive to caffeine should aim lower.
Why does timing matter?
Caffeine stays in the body for hours; late intake can disrupt sleep even if you feel fine.
Related calculators
Health
Water Intake Calculator
Daily water target based on body weight and activity.
Health
Calorie (TDEE) Calculator
Total Daily Energy Expenditure — daily calories needed to maintain, lose, or gain weight.
Health
BMI Calculator
Body Mass Index for adults, with WHO category interpretation.
Health
BMR Calculator
Basal Metabolic Rate via Mifflin-St Jeor — calories your body burns at rest.