Take an employee earning £50,000 in 2026/27. Class 1 National Insurance ignores the first £12,570, the primary threshold, so nothing is due on that slice. Earnings from £12,570 up to the £50,270 upper earnings limit are charged at the 8 percent main rate. Here the whole £37,430 between those two points falls in the main band, producing £2,994. Because £50,000 is below the £50,270 upper limit, none of the salary reaches the 2 percent additional-rate band, so total NI is £2,994, an effective rate of about 6 percent of gross pay.
How it is calculated
Class 1 employee National Insurance is banded like income tax but with its own thresholds. No NI is due on earnings below the primary threshold of £12,570 a year. Earnings between that threshold and the upper earnings limit of £50,270 are charged at the 8 percent main rate. Anything above the upper earnings limit is charged at just 2 percent, so very high earners pay a smaller marginal rate on the top slice. The calculator multiplies the pay inside each band by its rate and adds the two parts. This covers employees only. Self-employed people pay Class 4 NI on profits instead, and employer National Insurance is a separate cost on top.
Frequently asked questions
What about self-employed NI?
This calculator is for Class 1 (employees). Self-employed pay Class 4 NI on profits, see our UK Self-Assessment Calculator.
What is the primary threshold for National Insurance in 2026/27?
The primary threshold is £12,570 a year, the same as the income tax personal allowance. Earnings below this figure are free of employee National Insurance contributions.
Does National Insurance apply to pension contributions?
Salary sacrificed into a workplace pension reduces the pay subject to National Insurance, so pension contributions can lower your NI bill as well as your income tax. Contributions made outside a salary-sacrifice arrangement do not reduce NI.
Is National Insurance charged on all types of income?
Class 1 NI applies only to employment earnings such as wages, bonuses, and most taxable benefits in kind. Investment income, rental income, and state pension are not subject to employee National Insurance contributions.