The answer to this question depends on where you live and what kind of role you have. I'll give you a general answer that applies to most engineers and similar professionals. This answer does not apply to others.
For most parts of EM promotion of professional non-managers is determined by an Advancement Guide based on YEE and assessment. Each organization has a guide for each country. This is done to try and set a competitive pay level in each country. As a result, a VG performer in Chemicals in the UK might get promoted at a different YEE than a a VG performer in a different organization or different country.
Managers And some staff positions are handled differently. Most management positions have a CL range like 26-27 or 27-28. Getting promoted above the range requires getting moved to a higher level of management.
The exec levels are CL 30+ so most people retire below that level. To give yourself a good rule of thumb, assume that a VG engineer, or Department Head will retire around CL 28. To get to exec levels (30+) you need to be a Chief, exec manager, or exec staff. Again, as a rule of thumb, most execs report to a VP, regional director, large site manager (or above). So look at your organization. If you think you are going to be reporting to a VP or above when you retire assume you retire at CL 31. If you think your retirement job reports below VP then assume you retire at about CL 28. Use this to estimate the number of promotions until you retire.