Somewhat wrong and right

Ordinary wages is up to 6k per month cap.
So if you earn 7k. First 6k attracts cpf. Last 1k free to take home.

Maximum CPF ceiling per year is 102k however.
Why is this so? Cpf allows 30k of additional wages. Coz cpf thinks you have five month of bonus (102k=5months of 6k+12mth of 6k)


Case study 1: 102k evenly divided into 8.5k salary per month, no bonus. Take home pay 7300. CPF employee 1200. CPF employer 1020.
Annual take home pay : 87600
CPF employee: 14400
CPF employer: 12240
Total: 114240

Case study 2: 102k evenly divided into 6k salary per month, with 5 month bonus. Take home pay 4.8k per month. CPF employee 1200. CPF employer 1020.

Annual take home pay : 57600
CPF employee: 14400
CPF employer: 12240
Additional wages take home: 24000
Additional wages cpf employee: 6000
Additional wages cpf employer: 5100
Total: 119340


So you can see the additional 5.1k of employer contribution.
Some say cpf is good as it reduce your taxes, in case 2, your taxable income is reduced by 6k as it is squirrelled into CPF.