National Insurance Calculator
Calculate your National Insurance contributions for 2025/26. Employee, employer, and self-employed NI with current HMRC rates and thresholds.
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How to Use This Calculator
Employee NI tab
The default tab. Enter your annual gross salary and see your Class 1 NI breakdown instantly. The calculator shows NI at 8% on earnings between the Primary Threshold (£12,570) and Upper Earnings Limit (£50,270), plus 2% above UEL. Expand “More options” for multiple jobs and company director NI methods.
Employer NI tab
For business owners and HR teams. Enter the employee salary, pension contributions, and benefits in kind. See the full employer NI cost at 15% above the £5,000 Secondary Threshold, Employment Allowance offset (£10,500), Apprenticeship Levy (if payroll exceeds £3M), and total employment cost per employee.
Self-Employed NI tab
Enter your annual profit from self-employment. The calculator shows Class 4 NI (6%/2%) and optional Class 2 NI (£3.50/week for State Pension qualification). It also compares your NI to what an employee would pay on the same income.
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The Formula
National Insurance is calculated differently for employees, employers, and the self-employed:
NI = (min(Salary, £50,270) - £12,570) × 8%
+ max(0, Salary - £50,270) × 2%
Employer (Class 1 Secondary) 2025/26:
Employer NI = (NIable Pay - £5,000) × 15%
Net NI = Employer NI - Employment Allowance (up to £10,500)
Self-Employed (Class 4) 2025/26:
Class 4 = (min(Profit, £50,270) - £12,570) × 6%
+ max(0, Profit - £50,270) × 2%
Class 2 = £3.50/week × 52 = £182.00/year (voluntary)
The key difference between employee and self-employed NI: employees pay 8% on the main band while self-employed pay only 6%. This reflects the fact that employees also benefit from their employer paying 15% NI on top.
Employer NI is a hidden cost of employment — on a £35,000 salary, the employer pays an additional £4,500 in NI (before Employment Allowance).
Example
Chris — Marketing Manager, £42,000 salary
Chris earns £42,000 gross annual salary as an employee. His employer also pays 5% pension contribution (£2,100) and provides private medical insurance worth £800/year.
Employee NI (Chris pays)
Employer NI (Chris’s employer pays)
Chris’s true cost to his employer is £48,720 — that’s £42,000 salary + £4,620 employer NI + £2,100 pension. The employer NI alone adds 11% to the salary cost.