The maximum amount you can voluntarily contribute is the difference between the CPF Annual Limit of $37,740 and the mandatory CPF contributions made for the calendar year.

 

Do remember to consider your mandatory CPF contributions which you will be receiving for the calendar year, before making voluntary contributions. If the total mandatory CPF contributions and voluntary contributions exceed the CPF Annual Limit in the calendar year, any excess voluntary contributions will be refunded without interest in the following year.