From what I have been reading, GKI is calculated by taking your BG, dividing by 18 (if you’re in the US and not using millimoles) then dividing that by the reading on the keytone meter.
So for example:
BG = 70
Ketones = .5
70/18 = 3.88
3.88/.5 = 7.77
Is this calculation right?
Oh. I do it dividing BG by ketones and dividing that result by 18. Comes out the same though. 
Your arithmetic is correct, but I have no idea whether the formula is right or not. I do vaguely seem to remember something about dividing by 18 from a video by Dr. Boz. She’s the one who really pushes GKI.
So with the numbers I posted, a person would be in nutritional ketosis, but no autophagy would be happening?
Actually Dr Boz pushes the Boz ratio
BG (mg/dl) / BHB (mmol/dl)
GKI is (mg/dl)/18/BHB(mmol/dl) and was started by Dr Seyfried for his fasting cancer treatment.
BG / 18 converts mg/dl to mmol/dl
@DeeCS Just be aware that getting a Mojo is kind of like getting a color inkjet printer…
The reason the hardware is cheap is because you’ll be buying plenty of “cartridges.” That’s how they make a buck. 
In fairness, the Mojo’s BHB test strips are cheaper than competitors’ strips I’ve found - plus the actual Mojo device itself is outstanding in every respect. Since the glucose strips are rather cheap and the Mojo can test both, I’d suggest looking into their 50/50 strip promo package which has equal quantities (#50) of both. You shave a little off the “daily” usage price this way.
Over time, I’ve found that I don’t really have a compelling reason to test every day. Things begin to stabilize and it becomes more useful to see if anything you’ve eaten (or done) has had any measurable effect on your levels.
Regardless, it’s still probably cheaper to operate than a color inkjet printer, and loads more fun.
[Disclaimer: I use a Keto-Mojo and think it’s great (as does our family internist who’s on paleo eating).]
@SomeGuy I love your comparison to the ‘cheap’ ink jet printer and its expensive consumables! We can agree on some things!
Indeed, we agree! (But hopefully not too much, for then one of us become superfluous )
Yeah, that’s why I asked for it for my birthday, along with the 50/50 pack. I’m hoping I’ll be able to control myself and only check once a week or less.
Agree, lol. We ended up ditching our color inkjet printer (couldn’t even give it away on Freecycle) and got a black-only laserjet. Approximately the same price and the starter cartridge will print more sheets than we’ll ever use.
What’s the point? Human metabolism is a complex and dynamic system. It changes minute to minute. A once per week test for β-hydroxybutyrate tells you nothing about anything. It’s not worth the pain of pricking your finger. If you’re eating less than 20 grams of carbs per day and remain conscious you are in ketosis. Your weekly Mojo test will tell you nothing more.
LOL. I test my breathing once a week. I’m still alive. 
I’m afraid it’s time for us to disagree again…
While it’s certainly true that weekly testing provides far less granular data than daily testing, one could say the same about hourly vs daily, or “minute to minute” vs hourly. Doesn’t mean it’s not worth pricking your finger. Come on now @amwassil , that’s silly talk.
@DeeCS identifies herself as a former T2D and she’s trying to make further progress here. Confirming that you’re in ketosis (even if weekly) is both validating and encouraging, and given the significant changes in menu and meal timing, it’s helpful to know what’s going on under the hood - even if one’s budget makes it a just weekly peek.
Moreover, being able to determine whether different foods have a particular effect on one’s body has proven to be valuable data point for many of us who are still learning about our unique selves as we go along on this keto path. Wouldn’t reasonable encouragement toward this objective be more helpful?
Come on, Joey. Testing weekly for anything, other than still being alive, is useless. Eating sub-20 grams of carbs per day is a better confirmation of ketosis than a weekly Keto Mojo blood test.
@DeeCS If you want to confirm the status of your ketosis on an infrequent basis, you’d be better served by buying a Ketonix. The initial cost is more, but there are no consumables, so you can test as often as you wish without adding to your cost.
I thought that. Then I tested and realized my BG was way too high and K too low. It turns out one of my medications was jacking it up. I was only testing rarely as I couldn’t afford (unemployed :-)) to do it daily, but it did end up helping as a headsup.