Power bank for iPhone questions

[Freida]

Hello,

just looking for a power bank and wondered about how many times I can charge my iPhone.
If the bank is 10000mAh and my iPhone has battery around 1600mAh does that mean that I can charge my phone fully 5 times+ before the powerbank depletes itself? Or what is the assumption here, please?
I assume that some power is lost but is it a lot or little?

Thank you

also, anything to watch out for when buying a power bank?

 

[Yr Blues]

6 times, I would assume.

 

[nmeed]

My personal real world observation is that about every 5K gives me a full charge on my 12 Pro Max. So a 10K should give you 2-3 charges depending on your iPhone model. This might be a tad conservative but I think it's pretty safe.