CGT if not nominating our private residence

[someone]

To calculate your CGT you add up the days it was your PPR (and the last 18 months automatically qualify if it was ever your PPR so add them on if they're not included in the actual days you lived there). Call this A

You count the number of days you owned it. Call this B

The proportion that is exempt from CGT is A/B.

The proportion that is assessed for CGT is (B-A)/B

But if it's been let there's also residential letting relief. The amount of RLR depends on a number of factors but is capped at 40K.

And then the rate of tax you pay depends on what your total income is.

But if you've owned it for 20 years, lived in it for 8.5 years and then let for the next 11.5 years. And there's 100K gain.

PPR reduces the taxable gain to 50K
RLR reduces the amount assessed to 10K
CGT allowance of 11K

So no tax to pay at all.