How can I estimate how much minutes on the tape?

[gil900]

I think just looking at the weight of the film on the tape (the wheel ...)

But I do not know how many minutes equals one weight inch of film in the tape

[DB83]

What ?????????

Just play and time the darn thing.

[smrpix]

DB83's advice is the ony useful one. You've used tape and film interchangeably so no one knows what you're actually looking at. Diffrerent tapes have different base thicknesses and can be recorded at different speed so there's no single answer.