Caffeine remaining calculator
Add drinks with their type/amount and how many hours ago they were consumed. The tool uses a caffeine half-life model to compute remaining amounts and draws a decay graph.
How to use the form
- Type — Coffee or Tea use default mg/serving; choose Custom to enter exact mg per serving.
- Servings — each row represents a single serving; add multiple rows for multiple cups.
- Hours ago — how many hours have passed since you drank it (use decimals, e.g. 1.5 for 1 hour 30 min).
Type (mg per serving)
Hours ago
Actions
Summary
Projected decay (next 24 hours)
Defaults: coffee = 95 mg per cup, tea = 47 mg per cup. You can use Custom to enter mg per serving.