PSL

I'm potentially looking at switching to an agent at work and taking a % of the profit I make rather than being salaried as I think it will benefit me financially and give me a better quality of life but can't find any actual figures for tax and NI contributions on the net.

Is anybody here self employed and if so what % of your earnings do you put aside for tax and NI? Are there any break points etc?

Any help or advice gratefully received