Taxable computation

Hi, i will be working for full 6 months before my last employment here and i am an EP holder.  However, after the 6 months, i will be leaving back to my country. I was wondering how is the tax being computed. Will it be as 15% of total salary received for 6 months, e.g. 15% X $5,000 X 6months = $4,500 or it will be pro-rated?

There is a slab tax system on total income . It's not 15% direct cut on your 6 months income, please see the below link for your understanding:

https://www.iras.gov.sg/irashome/Indivi … culations/

You will be taxed as non-resident if you stay in Singapore for less than 183 days.
The non-resident income tax rate is either 15% on the income you received, or the resident rate in case it is higher. There are also some exemptions, which are explained at https://www.iras.gov.sg/irashome/Indivi … -Residents
In any case, the employer must (by law) withhold your salary of at least the last month, seek tax clearance with IRAS, pay the tax due from the withheld salary and then return the remainder (if any) to you. That means you must cover your last month of stay without receiving salary!