Present day compressors have pressure ratios over 25:1. With the addition of a fan pressure ratios of more than 25:1 are achived.
Compressor pressure ratio is available from manufacturer data.
For instance CFM56-5A3 pressure ratio=28; for an ambient inlet pressure of 14.7 psia the final pressure is 147x28=411 psia.
The pressure ratio will increase and decrease with engine speed. As inlet temperature increases, the compression ratio will tend to decrease due to the combined effects of air density decrease and the temperature effect on the angle of attack on the blades.
Regards