It's year 2020. How much is enough to retire in Singapore?

It depends on your expenses. 4% withdrawal rule suggest to have 25x of your annual expenses to retire. This is based on the assumption that your money is generating 7% return on yearly basis.

I remember reading a recent article about retiring in Singapore.

https://www.straitstimes.com/singapore/study-fi...

Based on basic standard of living, you will need $1,379 per month if your above 65. That's $16,548 a year. Do note that this is the bare minimum per the article. If you work backwards, assuming you will retire in 30 years time, it will be around $500k. I believe this is a very conservative estimate based on what is shared on the article.