£25,000 a year in benefits while working...or is the calculator wrong?

Hi all,

I have just checked the turn2us calculator to try and work out how much tax credits I could expect to receive when my third child is born.

It seems to think that I would get £25,000 a year in benefits despite earning £28,000 a year...I have tried it three times and it's giving the same outcome each time :/ is this correct?

I have childcare of £300 a week and rent privately at £550 a month.

Thanks in advance. If this calculator is not accurate, is there a better one to use? X