Class 2 & 4 National Insurance calculator
Self-employed National Insurance is mainly Class 4, charged at 6% on profits between £12,570 and £50,270 and 2% above that, under gov.uk's self-employed National Insurance rates. Class 2 is £0 once profits pass the £7,105 threshold. This estimates the Class 4 bill and confirms the Class 2 position.
What National Insurance do the self-employed pay?
There are two classes. Class 4 is the main one, charged as a percentage of profits: 6% on the slice between £12,570 and £50,270, then 2% on anything above £50,270, under gov.uk's self-employed National Insurance rates. Nothing is charged on profits below £12,570. Class 2 used to be a flat weekly charge, but there is nothing to pay if profits are above the Small Profits Threshold, and the year still counts towards the State Pension.
Below the Small Profits Threshold of about £7,105, Class 2 becomes voluntary. Paying it, at a low weekly rate, keeps the year on the National Insurance record, which can matter for the State Pension and some benefits. That is a personal decision, so it is left out of the headline figure.
How much Class 4 will I pay?
On £40,000 of profit, the Class 4 band that counts is £12,570 to £40,000, so 6% of £27,430 is an estimated £1,646. The profit does not reach £50,270, so there is no 2% band, and Class 2 is treated as paid at £0. The estimated National Insurance bill is therefore £1,646, on top of income tax. A profit above £50,270 would add 2% on the excess.
What are the Class 2 and Class 4 rates?
| Band | Rate |
|---|---|
| Profit up to £12,570 | No Class 4 |
| £12,570 to £50,270 | 6% |
| Above £50,270 | 2% |
| Class 2 (profit above £7,105) | £0, treated as paid |
Common questions
What National Insurance do the self-employed pay?
Class 4 on profits, at 6% between £12,570 and £50,270 and 2% above. Class 2 is a separate flat charge, but from 2024/25 there is nothing to pay for most people: if your profits are above the Small Profits Threshold of £7,105 the year still counts for the State Pension, treated as paid.
How much Class 4 will I pay?
On £40,000 of profit, Class 4 is about £1,646. That is 6% on the profit between £12,570 and £50,270. Nothing is due on the first £12,570, and the 2% band only starts once profit passes £50,270.
Do I still pay Class 2 National Insurance?
Not if your profits are above the Small Profits Threshold of £7,105, where it is treated as paid at £0. If your profits are below that you can pay Class 2 voluntarily to keep the year on your National Insurance record, which protects the State Pension and some benefits.
Is Class 4 the same as income tax?
No, they are separate. Class 4 National Insurance is charged on top of income tax on the same profits, and both are collected through Self Assessment. This tool covers the National Insurance only; use the Self Assessment estimator for the full bill.
What are the Class 2 and Class 4 rates?
No Class 4 is charged on profit up to £12,570. Between £12,570 and £50,270 the rate is 6%, and above £50,270 it drops to 2%. Class 2 is £0 once profit passes the £7,105 Small Profits Threshold, with the year still treated as paid for the State Pension.
Sources & Rate Verification
Rates verified against official statutory guidance on 6 September 2026.