Given below is a table that shows the relevant speeds with speed letters, which is seen at the sidewall of the tyre.
Be sure to check the manufacturers placard so the tyre you purchase meets the minimum requirements of your vehicle.
We hear this every day: "Oh I don't go that fast! I am not a racing driver!"
Please understand, it is not what speeds you do, but the speeds your vehicle is capable of doing. You need to meet the minimum requirements of your vehicle for legal reasons, if you order a tyre that is less than the minimum, the fitting station will refuse to fit the tyre.