How to work out loan repayment after being on Fixed Interest Rate?

Took out a Fixed Rate Mortgage a few years back and it will expire in December. Given the Interest Rate rises that have gone on over the last year or so I am trying to get a rough idea of what my new repayments will be if I go with Variable Rate when the Fixed Rate is up. So say:

I am 5 years into a 25 year mortgage with current balance owing of €210k

When I am entering the details into a Mortgage repayment calculator, do I put the new rate, the new oustanding balance and years left (20) or the actual amount of years of the original mortgage (25)?

Thanks.

Put in 210k over 20 years

Thanks a million for that.