There isn’t one specific formula – that’s the secret sauce. Discounted to it’s future value is as much an opinion as a math problem. Is it discounted because Wall Street doesn’t like it? Or is it discounted because it actually is a bad company and a bad investment? You have to make some assumptions.

But you can screen for criteria to give you companies that could fit your thesis:
– Price to Book value at 1 or less
– Low debt to equity ratio
– Rising free cash flow
– PEG ratio less than one

However, these are all estimates and guides to find undervalued companies.