UK National Insurance Calculator
Estimate your 2024/25 Class 1 National Insurance contributions as an employee.
How the UK National Insurance Calculator Works
Our UK National Insurance calculator estimates your 2024/25 Class 1 employee NI contributions based on your gross salary and any salary sacrifice arrangements. Enter your salary to see your annual, monthly, and weekly NI contributions, along with a band-by-band breakdown showing exactly how your National Insurance is calculated.
What Is National Insurance?
National Insurance (NI) is a tax on earnings that funds state benefits, including the State Pension, Statutory Sick Pay, and maternity allowances. If you're an employee, you pay Class 1 NI contributions, which are automatically deducted from your pay through PAYE alongside income tax. Your NI number is a unique identifier that tracks your contributions and determines your eligibility for certain benefits.
2024/25 National Insurance Rates and Thresholds
Class 1 employee National Insurance for 2024/25 is charged as follows:
- 0% on earnings up to £12,570 (the Primary Threshold)
- 8% on earnings between £12,570 and £50,270 (the Upper Earnings Limit)
- 2% on earnings above £50,270
The main rate was reduced from 10% to 8% in April 2024. The Primary Threshold is aligned with the income tax Personal Allowance at £12,570, meaning you start paying both income tax and NI on the same amount.
How National Insurance Is Calculated
NI is calculated on your gross earnings before any tax reliefs or pension deductions, but after salary sacrifice. The formula is straightforward:
NI = (Earnings between £12,570 and £50,270 × 8%) + (Earnings above £50,270 × 2%)
For example, someone earning £40,000 pays NI on £27,430 of earnings (the amount between £12,570 and £40,000). At 8%, their annual NI is £2,194.40, or approximately £182.87 per month.
Salary Sacrifice and National Insurance
Salary sacrifice reduces your gross salary before NI is calculated, which means you pay less National Insurance. For a basic-rate taxpayer, each £1 sacrificed saves 8p in NI on top of the 20p income tax saving. This is a key advantage of salary sacrifice over relief-at-source pension contributions, which only reduce income tax — not NI.
Employer National Insurance
Employers also pay National Insurance on your earnings — Class 1 Secondary NI at 13.8% on all earnings above £9,100 per year (the Secondary Threshold for 2024/25). This is paid by your employer and does not appear on your payslip as a deduction. However, with salary sacrifice, employer NI is also reduced, and some employers pass this saving on to you by increasing your pension contribution.
Self-Employed National Insurance
If you're self-employed, you pay Class 4 NI instead of Class 1. For 2024/25, Class 4 NI is 6% on profits between £12,570 and £50,270, and 2% above £50,270. Class 2 NI was abolished in April 2024. This calculator covers Class 1 employee NI only — if you're self-employed, use the Class 4 rates to estimate your contributions.
What This Calculator Does Not Include
- Income tax: Use our UK Tax Calculator or UK Salary Calculator for a full take-home pay estimate including income tax.
- Employer NI: The 13.8% employer contribution is not shown as it is not deducted from your pay.
- Self-employed NI: Class 4 rates differ from Class 1 employee rates.
- Student loan repayments: These are separate from NI and calculated on gross income above plan thresholds.
- Benefits in kind: Company cars and other benefits may have their own NI implications.
Frequently Asked Questions
For 2024/25, Class 1 employee National Insurance is charged at 8% on earnings between £12,570 (the Primary Threshold) and £50,270 (the Upper Earnings Limit), and 2% on earnings above £50,270. The main rate was cut from 10% to 8% in April 2024.
The Primary Threshold for 2024/25 is £12,570 per year, which is the same as the income tax Personal Allowance. You do not pay any National Insurance on earnings below this threshold.
The Upper Earnings Limit for 2024/25 is £50,270 per year. Earnings above this amount are taxed at the lower additional rate of 2% instead of the main 8% rate.
No. Self-employed individuals pay Class 2 and Class 4 National Insurance, which have different rates and thresholds. This calculator is for Class 1 employee NI only. Class 4 NI for 2024/25 is 6% on profits between £12,570 and £50,270, and 2% above £50,270. Class 2 NI was abolished in April 2024.
National Insurance funds specific state benefits including the State Pension, Statutory Sick Pay, and maternity allowances. Income tax funds general government spending. Both are deducted from your pay via PAYE, but they are calculated separately using different thresholds and rates.