Caffeine Cutoff Calculator

Stop your coffee from stealing your sleep.

Caffeine has a half-life of roughly 6 hours, which means the coffee you drink at 4am is still half-active at 10am when you are trying to sleep. The fix is not quitting caffeine. It is giving it a curfew. Enter the time you plan to be in bed and get your personal last-call.

Why a cutoff beats a ban

Night shift workers consistently report caffeine as both essential and destructive: essential at 2am, destructive at 9am. A cutoff gives you both. Front-load your caffeine in the first half of your shift, taper to water or herbal tea in the second half, and your sleep onset gets measurably easier within a few days.

What counts as caffeine

• Coffee: about 95mg per 8oz cup. The obvious one.
• Energy drinks: 150-300mg per can, plus sugar that adds its own crash.
• Pre-workout: often 300mg+. If you train after your shift, this is the silent sleep killer.
• Tea and chocolate: 30-70mg. Usually fine earlier in the shift, risky near bedtime.
• Some medications: check labels for headache and cold remedies that include caffeine.

The taper that actually works

1. First half of shift: drink caffeine freely. This is when you need alertness most.
2. After your cutoff: switch to water. Keep a big bottle at your station so the habit of sipping survives.
3. Last 2 hours: dim your environment if you can, avoid a heavy meal, and let your body start its wind-down before you even leave.

For the full strategy, read The Night Shift Caffeine Playbook.

General wellness information only. Talk to a clinician about caffeine use if you have heart conditions, anxiety, or take medication that interacts with stimulants.