To be under 50 mg of residual caffeine at an 11 PM bedtime, have your last 100 g of Cocoa Powder (230 mg) by 11:45 AM (11:45). The math uses the median 5-hour caffeine half-life; individual half-lives range from about 2 to 12 hours.
Cocoa Powder Last-Call Times by Bedtime
Latest time to finish 100 g of Cocoa Powder (230 mg of caffeine) and still be under 50 mg of residual caffeine at bedtime, assuming the median 5-hour half-life. Your personal half-life may sit anywhere in the 2 to 12 hour range.
| Bedtime | Last call for Cocoa Powder | Residual at bedtime |
|---|---|---|
| 9:00 PM (21:00) | 9:45 AM (09:45) | ~48 mg |
| 10:00 PM (22:00) | 10:45 AM (10:45) | ~48 mg |
| 11:00 PM (23:00) | 11:45 AM (11:45) | ~48 mg |
| 12:00 AM (00:00, midnight) | 12:45 PM (12:45) | ~48 mg |
Clearance Time by Serving Size
How long each serving of Cocoa Powder needs before bed to drop under 50 mg:
| Serving | Caffeine | Time needed before bed |
|---|---|---|
| 100 g | 230 mg | 11 h 1 min |
| 1 tbsp (5 g) | 12 mg | No wait needed |
Source: caffeine figures from USDA FoodData Central, FDC ID 169593 (SR Legacy, Cocoa, dry powder, unsweetened), accessed 2026-06-11. Values can vary by batch, location, and preparation; check the label or the source for the latest figures.
How the Math Works
Caffeine leaves your body by exponential decay. With the median 5-hour half-life, the 230 mg in 100 g of Cocoa Powder falls to 115 mg after 5 hours and 58 mg after 10 hours. To get under 50 mg, the level where caffeine stops measurably delaying sleep for most people, it needs about 11 h 1 min of clearance time. Subtract that from your bedtime and you get the last-call times above, rounded down to the nearest 15 minutes.
The big caveat: the 5-hour figure is a median. Depending on CYP1A2 genetics, medications, smoking, and pregnancy, real half-lives run from about 2 to 12 hours. If caffeine reliably keeps you up, treat these times as too generous and move your personal cutoff earlier, or model your own curve in the caffeine half-life calculator.