Check your picture dimensions.
If it's 4000×3000 pixels, that equals 12000000 pixels or 12MP.
What's confusing you is that the jpg images are a compressed file format.
Look closer at a number of images and you'll see the file size is different for each one and depends on the complexity of the image.
All blue sky and the size is smaller than a busy shot with lots of colour and detail.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.