
Find out when to stop using screens for optimal sleep
Calculate optimal screen-free time for better sleep
A blue light calculator determines when you need to stop using electronic screens and start dimming lights to protect your natural melatonin production. It calculates specific times based on your desired bedtime—typically 2 hours before bed for screens and 3 hours for bright overhead lights.
Blue light (460-480nm wavelength) from phones, laptops, and tablets tricks your brain into thinking it's daytime, suppressing melatonin production by up to 50%. Since melatonin starts building 2-3 hours before sleep, screen exposure during this critical window can delay sleep onset by 1-2 hours. Following the calculator's timeline helps you fall asleep faster and achieve deeper sleep naturally.

Good Night Lock helps you sleep better by automatically locking distracting apps during bedtime.
Download AppPerfect bedtime based on sleep cycles
When to stop coffee for better sleep
Measure your sleep quality
Create your evening routine
Beat jet lag when traveling
Perfect nap duration timer
When to stop using screens
Track your sleep deficit
Assess apnea risk
Ideal sleep temperature
Optimal bedtime for your child