I’ve tried to make them accurate but beware that I’m not a tax expert so there could well be errors. They have been created for interest only, not for serious use.
The first graph is showing how much income tax you pay depending on how much you earn. This graph is based on the standard un-adjusted tax free allowance of £6305, a 20% band for the next £34800 and 40% after that.
Next is a similar graph but for national insurance contribution. I’ve used £105 per week as being free from NICs, 11% for £105-£770 per week and 1% after that.
The third graph combines the total of the two to show the total taxation.
The final graph shows what percentage of your gross income you pay as tax. The interesting shape is caused by the National Insurance contributions changing to 1% before the 40% tax band kicks in.
You may spot that when your salary reaches just over £40k the percentage of salary that you pay in tax actually goes down by a very small amount before going back up again.