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Self-Employed National Insurance Calculator

Calculate your Class 2 and Class 4 National Insurance on self-employed profits for the 2026/27 tax year — with the Small Profits Threshold, effective rate and monthly/weekly breakdown.

Tool
£—

Your profits

£

Your taxable profit after allowable expenses (your Self Assessment profit figure).

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Self-employed NI Effective rate —

£—
Class 2 (flat weekly)£—
Class 4 (8% band)£—
Class 4 (2% above £50,270)£—
Class 4 total£—
Monthly£—
Weekly£—
2026/27: Class 2 £3.65/week (SPT £7,105) · Class 4 8% on £12,570–£50,270, 2% above

Self-employed National Insurance rates apply to the 2026/27 tax year (6 April 2026 – 5 April 2027). Source: GOV.UK — Rates and allowances: National Insurance contributions. Rules can change — check the latest official guidance.

How it works

Enter your annual self-employed profit. The calculator works out both Class 2 and Class 4 National Insurance. Class 2 is a flat weekly charge if your profits exceed the Small Profits Threshold (£7,105 in 2026/27). Class 4 is percentage-based: 8% on profits between £12,570 and £50,270, and 2% above £50,270.

Example calculation

For £40,000 self-employed profit (2026/27):

  • Class 2: profit ≥ £7,105 → £3.65/week × 52 = £189.80
  • Class 4 main (8%): £40,000 − £12,570 = £27,430 × 8% = £2,194.40
  • Class 4 higher (2%): profit below £50,270 → £0
  • Total NI: £2,384.20 — effective rate about 6.0%

Methodology & formula

Class 2 = £3.65/week × 52 if profit ≥ £7,105 (the Small Profits Threshold), otherwise £0.

Class 4 = 8% × max(0, min(profit, £50,270) − £12,570) + 2% × max(0, profit − £50,270).

  • Class 2 SPT: £7,105/year (up from £6,845 in 2025/26) GOV.UK · 2026/27
  • Class 2 rate: £3.65/week = £189.80/year GOV.UK · 2026/27
  • Class 4 lower limit: £12,570 (aligned with Personal Allowance) GOV.UK · 2026/27
  • Class 4 upper limit: £50,270 (aligned with Upper Earnings Limit) GOV.UK · 2026/27

Class 2 contributions count towards the State Pension and certain benefits. Class 4 does not give NI credits. Both are paid through Self Assessment by 31 January after the tax year.

Frequently asked questions

How is self-employed National Insurance calculated?
Self-employed workers pay two types of NI. Class 2 is a flat weekly rate (£3.65/week in 2026/27) if your profits are at least £7,105/year. Class 4 is percentage-based: 8% on profits between £12,570 and £50,270, and 2% on profits above £50,270.
What is the Small Profits Threshold?
The Small Profits Threshold (SPT) is £7,105 for 2026/27. If your self-employed profits are below this, you pay no Class 2 NI, though you can choose to pay voluntary Class 2 contributions to protect your State Pension record.
Do I pay Class 2 and Class 4 at the same time?
Yes. Both are calculated on your annual self-employed profits and paid through Self Assessment. Class 2 gives you NI credits for the State Pension and other benefits; Class 4 does not give credits — it is purely a revenue-raising contribution.
What are the Class 4 rates for 2026/27?
For 2026/27, Class 4 is 8% on profits between £12,570 and £50,270, and 2% on profits above £50,270. The lower and upper limits align with the employee NI Primary Threshold and Upper Earnings Limit.
Is self-employed NI the same as employee NI?
No. Employees pay Class 1 NI (8% between £12,570 and £50,270, 2% above), deducted through PAYE. Self-employed workers pay Class 2 (flat weekly) and Class 4 (8%/2% on profits) through Self Assessment. The self-employed generally pay less NI than employees on equivalent earnings.
When do I pay self-employed National Insurance?
Class 2 and Class 4 NI are paid through your Self Assessment tax return, usually by 31 January after the tax year ends. Payments on account may apply if your previous year's bill was over £1,000.

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Income Tax Calculator · Employee NI Calculator · Salary Calculator · Child Benefit Charge Calculator

Sources

Casvia provides educational calculators and general information. It does not provide personal financial, tax or investment advice.