How can you find the CMYK values for a pantone color?

By "Pantone Color," you must be referring to Pantone Solid or Pantone Spot Color, because Pantone is the brand of a private company that sets the international standard for print colors. "Pantone" does not indicate that something is not CMYK.

The mentioned company, Pantone, produces a swatch book called Pantone Bridge, and has the spot color on one column, and the CMYK process color on the other column so that you can see the color shift between solid and CMYK, as well as the CMYK breakdown. These swatch books are available online or in a local graphics supply store.