Ever wake up exhausted after a full 8 hours? The problem isn't how long you sleep — it's when you wake up. Best Time For Bed is a free sleep cycle calculator that figures out the exact times you should go to sleep or wake up, based on natural 90-minute sleep cycles. ✅ What makes it different: • Age-specific recommendations (teens, adults, seniors) • Works both ways — calculate bedtime OR wake-up time • Includes nap calculator, sleep debt tracker & sleep hygiene guides 100% free in browser