Caffeine Crash Calculator
Pulling an all-nighter? Find out exactly when your caffeine will wear off and when you can safely sleep.
Caffeine Crash Calculator
Find out when the coffee wears off and when you can sleep.
Guide: Espresso (60mg), Red Bull (80mg), Large Iced Latte (150mg), Pre-workout (250mg).
Caffeine Clear Time
2:00 AM
You need to wait approximately 12 hours before it leaves your system enough for a deep sleep.
How to use the Caffeine Crash Calculator
Enter the amount of caffeine you consumed in milligrams.
Enter the time of day you consumed it.
The tool uses the standard 5-hour half-life of caffeine to estimate when it will drop to sleep-safe levels.
More Uni Calculators
Free planning tools built for Uni coursework — no signup required.
Love Calculator
Test your match percentage online with our fun love test algorithm.
Open toolZodiac Sign Calculator
Find your astrological star sign instantly based on your birth date.
Open toolBirthstone Calculator
Discover your official birthstone, its color, and its traditional meaning.
Open toolDog Age Calculator
Find out exactly how old your dog is in human years based on their size.
Open toolSharehouse Rent Splitter
Split rent fairly based on bedroom sizes and ensuites.
Open toolHECS Repayment Time
Calculate how many years it will take to pay off your student debt.
Open toolFrequently Asked Questions
What is the half-life of caffeine?
The average half-life of caffeine in a healthy adult is about 5 hours. This means if you consume 100mg of caffeine, you will still have 50mg active in your bloodstream 5 hours later.
How much caffeine is in a coffee?
A standard single shot of espresso contains about 60-70mg of caffeine. A large milk-based coffee (like a large latte or flat white) often contains 2 shots, totaling 120-140mg.
When should I stop drinking coffee to sleep well?
Because of the 5-hour half-life, it is generally recommended to stop consuming caffeine at least 8 to 10 hours before your intended bedtime.