What’s Your Bulletproof ZQ Sleep Score? The Zeo Hack Every Sleep Hacker Needs To Know

By: Dave Asprey


The Zeo is a must have tool for sleep hackers – with a catch.

I was really excited I was when I first got my Zeo.  After years of sleep hacking and measuring the results based on how I felt, I could finally have exact quantitative metrics on how long I stayed in REM or deep sleep.  After some extensive testing, I knew my sleep hacking techniques made me feel great and I was alert and relaxed on minimal sleep.  However, I wanted more objective data.  Not only would it help me to prove that I wasn’t killing myself, it would allow me to test new techniques that could improve my sleep even more.

There was one problem – my ZQ was not as high as I expected most nights.

How could this be?  I was focused, alert, in good health, and refreshed even after just two hours of sleep.  I already ran a battery of tests to prove I was getting restorative sleep – so what was wrong with my Zeo sleep score?

The Zeo itself is amazing, but my score wasn’t nearly as high as I thought it should be.  Even though my REM and deep sleep were usually high as a percentage, my overall ZQ was low.

So I went to my friend (and cofounder/CTO of Zeo) Ben Rubin for answers.

He explained that the Zeo uses a simple algorithm that computes your total sleep time, REM sleep, deep sleep, time in wake, and how many times you were woken, then uses them to create your total ZEO sleep score, or ZQ.

Here is the formula:

ZQ= {(TST*1) + (REM*0.5 + Deep*1.5) – (TIW*0.5 + #wakenings/15)} *8.5

 ZQ = Zeo Sleep Score
TST = Total Sleep Time
REM = hours in REM
Deep = hours  in deep
TIW = hours in Wake
#wakenings = # of times you woke up

The ZQ score is heavily reliant on total sleep time.  The Zeo is expecting you to sleep at least 8.5 hours.  No matter what you do, if you sleep less than 8.5 hours a night – you’ll get a mediocre score. But we have study data that shows people who sleep less live longer. It’s not proof that sleeping less is good for you, but it’s proof it doesn’t have to be harmful, and the “8.5 hour rule” is probably not very scientific.

To see how important the difference is, I’ll show you what my score would be with two hours of Bulletproof sleep.  To make things simple, I’ve calculated this as if I spent half the time in REM sleep and half in Deep sleep.

ZQ= {((2)*1) + ((1)*0.5 + (1)*1.5) – ((0)*0.5 + (0)/15)} *8.5

This would give me a ZQ of only 34.  But is that really a problem?

So I modified this formula to solve this problem.  I’m calling it the “Zeo Force Multiplier.”  If your goal is to sleep more than 8.5 hours a night and wake feeling refreshed, then you can use the regular ZQ.

But if like me, you want to wake up feeling refreshed on less than 8 hours of sleep, you can adjust your score to tell you how good your sleep was based on how much you WANTED to sleep. To do that, you need to use the Zeo Force Multiplier.

Here’s how you would enter the data if your goal is to get only 2 hours of sleep. (I recommend you target 5 or more for longer terms)

  1. Get your ZQ score from your Zeo after you wake. Let’s say it was 40.
  2. Multiply your score by 8.5.
  3. Divide that number by the number of hours you wanted to sleep (5 in this case.)

Here’s how it looks in the equation:

ZQ score in the morning = 40
Goal: 5 hours of sleep

1. Multiply 40 by 8.5 to get 340

2. Divide 340 by 5

Your Bulletproof ZQ = 68

Now you have a number you can use to measure how efficient your sleep is in 5 hours. It’s theoretically possible (in a perfect world) to get a Bulletproof ZQ of 85 in 5 hours of sleep, evenly divided between deep and REM sleep. I haven’t done it yet.

There is no consistent research I’ve found for “hacked sleep” that says whether 50% deep and 50% REM are ideal, but that’s where I set my goals.  I know I won’t hit 50/50 all the time because of sleep and wake times.

Look out for a new blog post coming up on some cool new technology that increased my (always low) REM sleep by up to 500 percent. Stay tuned!

Please share your questions about the Zeo or sleep hacking in the comments and we’ll respond.