How much you need depends on the lifestyle you plan to have. One rule of thumb is that you need 2/3 of your last drawn salary to have the same standard of living pre-retirement.
For example, if you are earning RM6000/month now, and want to continue your current lifestyle during your retirement, you would need RM4000/month for your retirement years. You should also aim for enough retirement savings to last you 20 years. So if you need RM4000/month during retirement, you should save RM960,000.
In the previous question, we say that 20% of your income should be saved. Once you have enough fund for emergency (6-months of living expenses), you can then take 10% to 15% to fund for your retirement.
This means that if you are earning RM6000/month, RM600 to RM900 should be saved for retirement. However, you cannot rely on savings alone. RM900/month means you’ll take almost 90 years to save RM960,000, and you also have to take inflation into account. This is why it’s important to plan for your retirement!