This is the monthly instalment calculator for a HDB loan. Click HERE

Using the link above you can roughly calculate how much interest you pay for your flat per year.

Example sum of $100k loan
Over a 10 year period, you pay $1,376 in interest a year (or $13,760 in total interest).
Over a 30 year period, you pay $1,478 in interest a year (or $44,360 in total interest).

Therefore cramming your payment in 10 years effectively saves you $44,360 - $13,760 = $30,600 !!! This is enough to shove into investments for the next 20 years and earn you money instead.

Moral of the story - Take a smaller loan and pay it up FAST.