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Caffeine Intake Calculator

Daily caffeine from your drinks, against the recommended limit, with the half-life clearance.

Enter values

Results update as you type.

Result

Total caffeine

315 mg

Caffeine has a half-life of about 5–6 hours, so an afternoon coffee is still a third present at midnight.

Per kilogram of body weight
4.5 mg/kg
Of the 400 mg daily guideline
78.8%
Still in your system at bedtime
152 mg
Half-life
5.7 hours
Assessment
Moderate
Time to clear to 50 mg
15.1 hours

General guidance only. Health authorities commonly suggest a 400 mg daily limit for healthy adults and 200 mg in pregnancy — check with a clinician about your own circumstances.

About the Caffeine Intake Calculator

Daily caffeine from your drinks, against the recommended limit, with the half-life clearance.

Also known as: caffeine calculator, how much caffeine, caffeine limit, coffee caffeine content.

How to use this calculator

  1. Enter espresso shots, cups of filter coffee, cups of instant coffee, cups of tea and the other fields.
  2. The result updates instantly as you type — press Calculate (or Enter) at any time.
  3. Review the breakdown shown under the main result.
  4. Use Copy result or Share to save the answer or send a link with your inputs.

Formula

remaining = total × 0.5^(hours ÷ 5.7)

Worked example

Using the values pre-filled in the calculator above:

  • Espresso shots = 2
  • Cups of filter coffee = 1
  • Cups of instant coffee = 0
  • Cups of tea = 2
  • Energy drinks = 0
  • Cans of cola = 0
  • Body weight = 70 kg
  • Hours before bed = 6

the calculator returns:

  • Total caffeine: 315 mg
  • Per kilogram of body weight: 4.5 mg/kg
  • Of the 400 mg daily guideline: 78.8%
  • Still in your system at bedtime: 152 mg