🇬🇧 National Insurance Calculator
Calculate UK NI Contributions for 2025/26 Tax Year
📊 Understanding National Insurance
The National Insurance calculator helps UK employees, self-employed individuals, and employers calculate their NI contributions for the 2025/26 tax year. National Insurance funds the State Pension, benefits, and NHS. Employees pay Class 1 NI at 8% on earnings between £12,570-£50,270, then 2% above. Self-employed workers pay Class 2 (£3.45/week) plus Class 4 (6% then 2%) on profits. Employers pay 13.8% on earnings above £9,100. This calculator shows your exact NI liability, effective rates, and monthly deductions—essential for payroll planning and tax estimation.
📝 How to Use the National Insurance Calculator
- Select Your Status: Choose the Employee, Self-Employed, or Employer tab based on your situation.
- Enter Your Income: Input your annual gross salary (employees) or net profit after expenses (self-employed).
- Select Pay Frequency: Choose weekly, bi-weekly, monthly, or annual to see period-by-period breakdowns.
- Choose NI Category: Most employees are Category A (Standard). Select other categories for apprentices, under-21s, or those over State Pension age.
- Click Calculate: View your annual NI, monthly deductions, effective rate, and detailed band breakdown.
Employee NI (Class 1)
Self-Employed NI (Class 2 & 4)
Employer NI (Class 1 Secondary)
📐 National Insurance Formula & Calculation Method
Employee NI (Class 1)
Employees pay 8% on earnings between the Primary Threshold (£12,570) and Upper Earnings Limit (£50,270), then 2% on anything above. No NI is due on the first £12,570.
Self-Employed NI (Class 2 + 4)
Class 2 is a flat weekly rate for State Pension credits. Class 4 is profit-based—6% on profits between £12,570-£50,270, then 2% above. Class 4 rates are lower than employee rates.
Employer NI (Class 1 Secondary)
Employers pay 13.8% on all earnings above the Secondary Threshold (£9,100/year). The £5,000 Employment Allowance can offset this for eligible small employers.
📊 National Insurance Examples
Example 1: Employee on £35,000/year
Scenario: Sarah works as a marketing manager earning £35,000 annually.
Inputs: Salary: £35,000 | Category A (Standard)
Calculation:
- Earnings in main band: £35,000 − £12,570 = £22,430
- NI at 8%: £22,430 × 8% = £1,794.40
- Upper band: £0 (salary below £50,270)
Result: Annual NI: £1,794 | Monthly: £149.50 | Effective rate: 5.13%
Example 2: Self-Employed with £50,000 Profit
Scenario: James is a freelance consultant with £50,000 net profit.
Inputs: Profit: £50,000 | 52 weeks self-employed
Calculation:
- Class 2: £3.45 × 52 = £179.40
- Class 4 Main: (£50,000 − £12,570) × 6% = £2,245.80
- Class 4 Upper: £0 (profit below £50,270)
Result: Total NI: £2,425 | Effective rate: 4.85%
Example 3: High Earner on £75,000/year
Scenario: David is a senior developer earning £75,000 annually.
Inputs: Salary: £75,000 | Category A (Standard)
Calculation:
- Main band: (£50,270 − £12,570) × 8% = £3,016
- Upper band: (£75,000 − £50,270) × 2% = £494.60
Result: Annual NI: £3,511 | Monthly: £292.55 | Effective rate: 4.68%
📊 2025/26 NI Rates & Thresholds
| Threshold | Weekly | Monthly | Annual |
|---|---|---|---|
| Lower Earnings Limit | £123 | £533 | £6,396 |
| Primary Threshold (Employee) | £242 | £1,048 | £12,570 |
| Secondary Threshold (Employer) | £175 | £758 | £9,100 |
| Upper Earnings Limit | £967 | £4,189 | £50,270 |
Source: GOV.UK - Official National Insurance Rates 2025/26
💡 Important Tips for National Insurance
- 2024 Rate Cuts: Employee NI was reduced from 12% to 8% in April 2024. Self-employed Class 4 dropped from 9% to 6%. These are significant savings.
- State Pension Credits: Earning above the Lower Earnings Limit (£6,396) qualifies you for State Pension credits, even if you pay no NI.
- Employment Allowance: Employers with NI bills under £100,000 can claim up to £5,000 off their annual employer NI. Check eligibility at GOV.UK.
- Category Matters: Under-21s (M) and Apprentices under 25 (H) have different employer rates. Check you're on the right NI category.
- Self-Assessment: Self-employed NI is calculated and paid through Self Assessment. Budget for Class 2 + Class 4 when estimating taxes.
- Voluntary Contributions: You can pay Class 3 voluntary contributions to fill gaps in your NI record for State Pension purposes.
🔗 Related Calculators
❓ Frequently Asked Questions
📚 Official Resources
Created by Omnicalculator.space — Your trusted source for UK tax and NI calculators.
Last Updated: January 2026 | HMRC 2025/26 Rates