Depending on two assumptions:
- Efficiency
- % VO2max at FTP
the VO2max (relative) can vary quite a bit:
and here are the standards for VO2max by age
Source: Edge 530 - VO2 Max. Standard Ratings
In any case, you can see there are wide swings in VO2max based on your fractional utilization (FTP as % of VO2max) and efficiency. One of several reasons that FTP is considered the single largest determinant of performance.

