In response to the recent 'budget frenzy' and the speculation about whether Labour were about to break their manifesto promises (they did in the end!), I revived an offline tax calculator I generated some years ago and brought it up to date with all the current tax bands and allowances. With the advent of Burnham's proposed 'additional' taxes, I've added an extra worksheet containing calculators for a Wealth Tax, Revised IHT and Care Levy, and Land Tax, with thresholds and rates, as far as we know them as of July 2026.
The Tax and NI calculators run under MS Excel (v2010 onwards), and have all the current parameters required to work out tax due on earned and unearned income. All you need to enter is your total projected earnings for the year and your personal tax allowance. It will also accomodate Capital Gains and National Insurance calculations.
The big advantage of using an offline calculator is that you won't be taking the risk of sharing your intimate financial details with the rest of the internet...including any potential hackers looking out for well-off victims to scam.
You can download the Excel file (Taxsheet.xlsm) from my downloads page. You'll need to allow macros to get the calculation to run - you can either do this each time you load the file, or just adjust your Excel security settings.
Happy calculating....hope you find you can still make ends meet after 'our Andy' has taken his extra cut(s) this year !