how the calculation work ?

if fix rate 2.5% , borrow 100k for 9 years , total repayment = 9 *2.5k =22.5k
+ 100k = 122.5k

if floating rate, let say 3% and every month u pay 900
1st year 100k *3% = 3k
2nd year 100k - (900*12) + 3k ( interest) = 92.2k * 3% = 2766
and goes on, when your base reducing, the interest goes cheaper

so it depends on the floating rate provided, if very near fix interest rate, flexible better

not to mention you able to throw cash upfront to reduce interest ( if follow house loan method la )