How much National Insurance do sole traders pay?

There is Class 2 and Class 4 National Insurance.

Class 2 is paid on profits of £6,515 or more a year and is £3 per week.

Class 4 is paid on profits of £9,569 or more a year and is 9% on profits between £8,632 and £50,270 and 2% on profits over £50,270.