When to stop drinking black tea, decaf
Black tea, decaf · 8 oz holds about 2 mg of caffeine — at that level it barely moves your bedtime number, whatever your sensitivity. The table says the same thing in nine cells.
Finish your last one by
—
Your 2 mg over the next 16 hours
| Bedtime | Sensitive · 25 mg | Standard · 50 mg | Tolerant · 100 mg |
|---|---|---|---|
| 10:00 PM | 10:00 PM | 10:00 PM | 10:00 PM |
| 11:00 PM | 11:00 PM | 11:00 PM | 11:00 PM |
| 12:00 AM | 12:00 AM | 12:00 AM | 12:00 AM |
Source — USDA FoodData Central (SR Legacy 174871), checked 2026-10-13. 1 mg per 100 g × 237 g ≈ 2 mg.
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Common questions
When should I stop drinking black tea, decaf before bed?
For a 23:00 bedtime at standard sensitivity (50 mg bedtime limit), finish your last black tea, decaf by 11:00 PM. Sensitive readers should shift earlier; tolerant readers later.
Why do the times differ so much between people?
Caffeine half-life ranges 1.5–9.5 h across healthy adults, and dose differs by drink. The same can that clears a fast metabolizer by dinner can still be 50 mg in a slow one at midnight.
Method
Cutoff = bedtime − T½ × log₂(dose ÷ limit), base T½ 5 h, limits 25/50/100 mg. Every cell is computed, not quoted — the cutoff calculator applies the same formula with your metabolism factors.