National Insurance will be reduced from 12% to 10% on workers' incomes between £12,570 and £50,270 from Saturday. The changes, announced by the Prime Minister in the autumn, will affect around 27 million payroll workers across the UK. Someone on the UK average salary of £35,000 could save £450 a year, or £37.38 per month, with this change. Use our tool below for a rough guide to what tax changes can be expected for most people, as there are other variables not included which might affect how much tax you pay including being in receipt of the blind person's allowance or the marriage allowance. It also assumes you are not self-employed and are under pension age... There are also national insurance cuts for the self-employed too, from April. This includes the scrapping of Class 2 contributions, as well as a reduction of the rate of Class 4 contributions from 9% to 8% for the £12,570 to £50,270 earnings bracket. These will impact nearly two million self-employed people, according to the Treasury. While many campaigners welcomed the national insurance announcement last autumn, they pointed out that the tax burden remains at record high levels for Britons - thanks in part to the threshold at which people start paying income tax being frozen, rather than rising with inflation.