I second the @joojaa's answer and would like to add that trying to match colors across different devices is really only feasible in a color calibrated workflow. I see a lot of small print shops that don't use a color calibrated workflow. Bottom line, in my experience (10 years in the industry), is: if color matching is important, use a color calibrated workflow and find a printer that uses and understands it.
About a year ago I created a swatch book (brand colors) for a client. My workflow is color calibrated and I have the experience to understand its pitfalls. However, when choosing printer I made a mistake. The printer would (without asking) manually edit the the cmyk values in his printer to match some color he thought looked better. When I noticed the colors were off I started asking about their workflow and realized this was common practice with them and they didn't have the faintest idea what a color calibrated workflow is about. I was pressed on time and would not change printer in the middle of the job so I worked with them and manually edited the cmyk values in the printer to match the color on my calibrated screen (target profile ISO Coated 300%). The end result was OK, but what a waste of time.
Printers should know color management. If not, choose someone else.