Sleep & Coffee Speed

Caffeine Speed & Sleep Cut-Off Calculator

Understand how your CYP1A2 liver enzyme clears caffeine, why coffee affects sleep latency differently, and calculate your personalized evening coffee curfew.

📖 Understanding Coffee Clearance & Sleep

Caffeine clearance is governed primarily by your liver's CYP1A2 enzyme speed and your brain's ADORA2A adenosine receptors:

  • Fast Coffee Clearers (CYP1A2 A/A): Process 50% of ingested caffeine in 2 to 4 hours. Morning or early afternoon coffee leaves minimal residual caffeine by bedtime.
  • Slow Coffee Clearers (CYP1A2 A/C or C/C): Retain active caffeine in blood plasma for 8 to 10+ hours. A 2:00 PM coffee can linger into bedtime hours.
  • Deep Sleep Impact: Even if you fall asleep easily, carrying >20mg of residual caffeine at bedtime blocks adenosine sleep pressure receptors, suppressing Stage N3 slow-wave deep sleep.

Read our full CYP1A2 Coffee Clearance Gene Guide or explore Caffeine Clearance & Sleep Latency.

Interactive Calculator

⚡ Calculate Your Bedtime Caffeine Level & Cut-Off Curfew

Select your coffee clearance speed, intake dose, and target bedtime below to calculate your residual mg and recommended last-cup cut-off time.

150 mg
Estimated Half-Life
6.0 hrs
Bedtime Residual
31.2 mg
Recommended Cut-Off
11:30 AM
Sleep Impact Score
78/100
Mild Sleep Risk

💡 GenoTaste Recommendations

  • If carrying slow clearance status, shift your last coffee dose before 12:00 PM.
  • Incorporate green tea or matcha in the early afternoon for natural L-theanine calming support.
  • Have an existing DNA report? Book a GenoTaste Report Clarity session to personalize your complete sleep and energy blueprint.
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