Part of being an adult is getting to decide your own bedtime. Which is awesome. The downside is that you don’t get to decide your wake up time usually. The Sleepyti.me Bedtime Calculator is a simple site that helps you figure out when it’s best to go to bed.

The site is simple, featuring only the options to calculate when you should go to bed or when you should ideally wake up. The suggested times are based on REM cycles. Have you ever been fast asleep, deep in dreaming and your alarm goes off? Think about how that felt. Horrible, right? Sleepyti.me gives you the most likely times when you’ll be in between cycles and your sleep is at its lightest, meaning you wake up much easier.

If you’re a responsible adult and already know your bedtime (and plan to stick with it instead of clicking refresh on Facebook or watching one more episode of something on Netflix) then you can input that information and find out when it would be best for you to wake up.

Sleepyti.me Bedtime Calculator is a free web site app.