National Insurance (NI) Calculator
Estimate employee and employer National Insurance contributions from your annual earnings.
What is a nat ins calculator?
A nat ins calculator helps you estimate how much National Insurance (NI) is deducted from employment income in the UK. For employees, NI is usually calculated automatically through PAYE payroll, but a calculator is useful when you are comparing job offers, planning a pay rise, or checking your payslip.
This tool focuses on Class 1 contributions for a standard employee setup and also gives an employer-side estimate. It is designed for quick planning, not official payroll filing.
How this calculator works
The calculator annualises your pay and applies threshold bands for the selected tax year:
- Employee NI: 0% up to the Primary Threshold, main rate in the middle band, and additional rate above the Upper Earnings Limit.
- Employer NI: employer rate on earnings above the Secondary Threshold.
- Pay period view: annual NI divided into monthly, weekly, or annual display.
| Tax Year | Primary Threshold (Employee) | Upper Earnings Limit | Main / Additional Employee Rate | Secondary Threshold (Employer) | Employer Rate |
|---|---|---|---|---|---|
| 2026/27 | £12,570 | £50,270 | 8% / 2% | £5,000 | 15% |
| 2025/26 | £12,570 | £50,270 | 8% / 2% | £5,000 | 15% |
| 2024/25 | £12,570 | £50,270 | 8% / 2% | £9,100 | 13.8% |
How to use it in 30 seconds
1) Enter your annual salary
Use your gross base salary before tax and deductions. If you expect regular bonuses, include them in extra taxable pay.
2) Pick your tax year
Thresholds and rates can change by year, so always choose the right period.
3) Read both annual and pay-period outputs
The annual result helps with planning, while monthly/weekly results are handy for payslip checks and budgeting.
Why NI estimates matter for decisions
When you evaluate compensation, focusing only on gross salary can be misleading. NI affects your take-home pay and can change at different income bands. A quick estimate helps you:
- Compare two offers with different bonus structures.
- Estimate the impact of overtime or second-job income.
- Understand the marginal deduction on raises.
- Plan cash flow more accurately each month.
Frequently asked questions
Is this the same as income tax?
No. NI is separate from income tax. This calculator estimates NI only.
Does this include student loan or pension deductions?
No. Student loan, pension contributions, and other deductions are not included in the NI figure shown here.
Can I use this for self-employment?
Not directly. Self-employed contributions (Class 2 and Class 4) follow different rules and should be calculated separately.
Bottom line
A good nat ins calculator gives you clarity before payday. Use this one as a fast estimator, then validate against your payroll software or accountant for official reporting. Even a rough NI forecast can improve salary negotiations, savings targets, and month-to-month budgeting.