Calculation used when working out tax on savings interest & employment income

What is the calculation used when working out tax due on employment income & savings interest over the Personal savings allowance as there appears to be conflicting info on the HMRC website calculation guides as to how the calculation is done If for example & this is just an example , the total income was over £52000 which included interest over £1000 would you then deduct the personal allowance of £12,570 from this which would leave a total of £39430 which based on this would mean it was in the 40% tax band so you would therefore only have a personal savings allowance of £500. Do you then deduct the £500 PSA from this leaving a total taxable income of £38930 which would mean that £37700 of this would be taxed at 20% & the remaining difference of £1230 would be taxed a 40%.

Hi ,
 

That's correct. See :  Income Tax rates and Personal Allowances   .

Thank you .