Calculator for working out interest and penalties

Hello, I have some rental income from a few years ago that I'm in the process of making a disclosure to HMRC for. No excuses, I've just been an idiot. When using the calculator supplied by HMRC for working out Income tax, Capital Gains tax, Class 4 National Insurance contributions, Interest and Penalties - if one of the years being reported has made a loss, is this entered into the form in the rental income box as a negative value, or is this not reported? If I enter it, it subsequently provides a negative value in the income tax due summary table, reducing the overall figure for the years where tax was due. I hope this makes sense, any help would be much appreciated.

Hi ,
 

You still need to report it as you can then carry forward the loss to use against a laters years rental profit . Thank you .