TIF file size question

[PeterAit]

I have a TIF image that is 5382 x 3600 or 19,375,200 pixels. It is an RGB file at 16 bits / component which I interpret as meaning it takes 6 bytes / pixel. Multiply and I get a file size of  116,251,200 bytes. Add some for metadata and other stuff so let's say 117 MB. Yet the file on disk is 618 MB. Why is this? Thanks.

[MfAlab]

Check is there any layers and/or channels. Flatten the image and delete additional channels, and you will get the numbers in calculation.

[digitaldog]

Reported on disk through the Finder or Photoshop?
It's late but as I see it: 5382 x 3600 or 19,375,200 pixels times 3 bytes per pixel (RGB). Divide that by 1024 and then double that for 16-bits. 113mb is pretty close to that 117mb reported.

[mcbroomf]

Check is there any layers and/or channels. Flatten the image and delete additional channels, and you will get the numbers in calculation.

^ Yep ...

Create a new 16 bit colour file of those dimensions and see what you get.  PS reports 110MB to me, Win Explorer 113mb.  To get over 600mb there are additional layers or channels.