National Insurance Calculator UK
Calculate your UK National Insurance (NI) contributions for the 2024/25 tax year. This calculator covers Class 1 (employed), Class 2 (self-employed), and Class 4 (self-employed) contributions.
NI Summary
NI Breakdown
2024/25 NI Rates
Understanding UK National Insurance
National Insurance (NI) contributions are payments made by employees, employers, and self-employed people to fund state benefits and the NHS. There are different classes of NI depending on your employment status and income level.
NI Classes and Rates 2024/25
National Insurance Classes
Class 1 - Employed
For employees earning above £12,570
Split between employee and employer
Main rate: 8% (employee), 13.8% (employer)
Upper rate: 2% over £50,270
Class 2 - Self-Employed
Flat rate for self-employed
£3.45 per week (2024/25)
Small profits threshold: £6,725
Over pension age: exempt
Class 4 - Self-Employed
Profit-related contributions
Main rate: 8% on profits £12,570-£50,270
Upper rate: 2% on profits over £50,270
No upper limit
NI Thresholds and Rates
| Threshold/Rate | 2024/25 Amount | Description |
|---|---|---|
| Primary Threshold | £12,570 | No NI below this level |
| Upper Earnings Limit | £50,270 | Reduced rate above this |
| Secondary Threshold | £9,100 | Employer contributions start |
| Small Profits Threshold | £6,725 | Class 2 exemption |
Class 1 NI Calculation
How Class 1 NI is Calculated
Employee Contribution (Primary)
8% on earnings £12,570 to £50,270
2% on earnings over £50,270
Employer Contribution (Secondary)
13.8% on earnings £9,100 to £50,270
13.8% on earnings over £50,270
Total Cost to Employer
Gross salary + employer NI + other costs
Self-Employed NI
Class 2 Contributions
- Flat weekly rate: £3.45
- Exempt if profits under £6,725
- Exempt over pension age
- Paid weekly or monthly
Class 4 Contributions
- 8% on profits £12,570-£50,270
- 2% on profits over £50,270
- Paid through Self Assessment
- No upper limit
NI Category Letters
NI category letters determine which rates and thresholds apply to your earnings. The most common is category A (standard employee). Other categories may apply to apprentices, deferred employees, or those over pension age.
Benefits from NI Contributions
NI contributions fund various state benefits including the State Pension, Jobseeker's Allowance, maternity leave, and the NHS. The amount you can claim depends on your contribution record and the type of benefit.
Payment and Deadlines
Employee NI is deducted automatically from wages. Self-employed Class 2 is paid weekly or monthly, while Class 4 is paid through Self Assessment. Late payment can result in penalties.
Key Takeaways for UK NI
- Class 1 for employees, Classes 2 & 4 for self-employed
- Main rate 8% for earnings £12,570-£50,270
- Upper rate 2% for earnings over £50,270
- Employee pays primary, employer pays secondary
- Self-employed pay both Class 2 (flat rate) and Class 4 (profit-related)
- Funds state benefits and NHS
- Category letters determine applicable rates
- Payment deadlines vary by class