I suppose, your design starts with a given value for Ic, correct?
Hence, you know the corresponding value for the base current Ib (based on a given current gain value).
More than that, I assume you have fixed already the values for Rc and Re.
Because of Ie=Ic+Ie you know the voltage at the emitter node as well as on the base node (0.65...07 V larger).
With these information you can design the voltage divider at the base.
Don´t forget that it is a LOADED divider (load=base node).
During calculation you have to make some assumptions:
1.) Vbe=(0.65...0.7): Choice of the value is of less importance because of Re feedback, which stabilizes the DC operating point,
2.) Resistance niveau of the voltage divider: It is common practice to select resistances which allow a current through the divider chain which is approximately (6...10) times the base current.
(Explanation: You have to find a trade-off. Small resistors give an unwanted small signal input resistance, but allow a good dc stabilizatin - and vice versa).