National Insurance Calculator — Employee, Employer, Class 4 & Class 2 (2026/27)

National Insurance is not one tax — it is up to four, and which ones you pay depends on where the money comes from. A salary carries Class 1, split between what comes out of your pay (employee) and what your employer pays on top (employer). Self-employment profit carries Class 4 and, below a small threshold, an optional Class 2. Rental income carries none of them. This calculator adds up whichever apply to the figures you enter, for 2026/27, and works UK-wide — National Insurance uses the same rates and thresholds in England, Scotland, Wales and Northern Ireland; only income tax bands differ by nation (Scotland has its own), not National Insurance.

Employed: Class 1, in two parts

On a salary, you personally pay employee Class 1 at 8% on earnings between £12,570 (the Primary Threshold) and £50,270 (the Upper Earnings Limit), then 2% above that. On a £30,000 salary that is £1,394 a year. Separately, your employer pays employer Class 1 at 15% on everything above the £5,000 Secondary Threshold — £3,750 on that same salary. It is not deducted from your pay; it is an extra cost to your employer, which is why it only shows here for context.

Self-employed: Class 4 and the Class 2 choice

Class 4 works the same way as employee Class 1 but on profit, not salary: 6% between £12,570 and £50,270, then 2% above — £1,046 on £30,000 of profit. Class 2 is different: once profit reaches £7,105 a year, HMRC treats it as already paid — you get the qualifying year for free. Below that, it is entirely optional, at £3.65 a week (£190 a year); paying it voluntarily is usually the cheapest way to buy a qualifying year toward the State Pension if your profit is too low to get one automatically.

Doing both, and what does not count at all

Have a job and a side self-employment (or a rental)? Class 1 and Class 4 are simply worked out separately and added together — there is no combined allowance between them. The one relief that exists for multiple income sources is narrower than it sounds: HMRC's deferment scheme (form CA72A) only covers employee Class 1 across two or more employments, and explicitly does not extend to the self-employed — "you cannot defer Class 4 contributions" if you also run a self-employment alongside a job. Rental income sits outside National Insurance altogether: this site’s own verified data confirms no NIC-on-rents charge has not been introduced, so a landlord’s rental profit — employed, self-employed or neither — never appears in this calculator’s total.

When it stops

National Insurance is not for life. Employee Class 1 stops the day you reach State Pension age, even if you keep working; Class 4 stops from the following 6 April. Your employer’s Class 1, however, keeps being paid on your salary regardless — gov.uk’s own rate tables show employees above State Pension age (category letter C) paying nil while the employer rate stays at 15%. State Pension age itself is not fixed: it is currently being phased from 66 up to 67 between 2026 and 2028, for people born from 6 April 1960 onward, with a further rise to 68 legislated for the mid-2040s (and flagged, but not yet legislated, for as early as the mid-2030s).

Where this fits with the rest of your tax

This is one page of the picture. The take-home pay calculator puts income tax and National Insurance together to show what actually lands in your account; the self-employed tax calculator adds payments on account on top of the Class 4 and Class 2 figures shown here; the income tax calculator handles salary, profit, rent, pension and dividends together for the tax side; and the rental income tax calculator is where the property side of a combined income actually gets taxed — since, as above, it never carries any National Insurance.

Class 1 employee/employer rates and thresholds and the category-C (State Pension age) rate: gov.uk, "Rates and thresholds for employers 2026 to 2027", read 13 September 2026. Class 4 and Class 2 rates, thresholds and the £7,105 treated-as-paid rule: gov.uk, "Self-employed National Insurance rates", read 13 September 2026. When National Insurance stops: gov.uk, "National Insurance", read 13 September 2026. State Pension age timetable: gov.uk, "State Pension age timetable", read 13 September 2026. Multiple-income deferment: gov.uk, "Defer National Insurance", read 13 September 2026. Rental income and National Insurance: this site’s taxdata.py, verified against gov.uk 29 August 2026. General information for England, Scotland, Wales and Northern Ireland, not advice — your own National Insurance record (categories, credits, gaps) is checked on your personal tax account.