- Standard Category A National Insurance rates, which apply to most employees. Apprentices under 25, under-21s, veterans and some other categories use different rates not covered here.
- On the Employed tab, National Insurance is worked out for the single pay period you enter, using that period’s own threshold — it is not cumulative across the year the way Income Tax is.
- The “annualised” figures shown assume your pay stays the same every period all year. Irregular pay, bonuses, or a change in earnings partway through the year will change your actual annual total.
- This calculator covers National Insurance only, not Income Tax, student loans, or pension contributions.
- This is a simplified estimate, not a payroll replication. Real payroll calculations can involve additional payroll-specific rules and circumstances — for example directors’ National Insurance, multiple employments, or contracted-out arrangements — that aren’t covered here.
National Insurance Calculator
Work out your Class 1 employee National Insurance contributions for 2026/27, based on your gross pay and pay frequency.
National Insurance Breakdown
Each band shows how much of your pay falls into it, and the National Insurance charged on that portion.
Self-Employed National Insurance Calculator
Work out your Class 4 National Insurance for 2026/27, based on your annual trading profit, plus whether voluntary Class 2 applies to you.
Class 4 National Insurance Breakdown
Each band shows how much of your profit falls into it, and the National Insurance charged on that portion.
National Insurance Calculator UK 2026/27
Our National Insurance Calculator works out your Class 1 National Insurance if you’re employed, or your Class 4 National Insurance if you’re self-employed, using confirmed 2026/27 HMRC rates and thresholds. Use the Employed tab to check National Insurance on a weekly, fortnightly, 4-weekly, monthly, or annual payslip figure, or the Self-Employed tab to work out Class 4 on your trading profit and check whether voluntary Class 2 applies to you.
How to Use This Calculator
- Choose a tab: Employed for Class 1 National Insurance on a salary, or Self-Employed for Class 4 on trading profit.
- On the Employed tab, select your pay frequency (weekly, fortnightly, 4-weekly, monthly, or annual) and enter your gross pay for that period.
- On the Self-Employed tab, enter your annual taxable trading profit.
- Click Calculate to see your National Insurance due, effective rate, and a full band-by-band breakdown.
National Insurance Rates for 2026/27
| Class | Who Pays It | Rate | Thresholds |
|---|---|---|---|
| Class 1 (employee) | Employees, via PAYE | 8% then 2% | £12,570 to £50,270 a year, then above |
| Class 4 | Self-employed, via Self Assessment | 6% then 2% | £12,570 to £50,270 a year, then above |
| Class 2 (voluntary) | Self-employed with profits below £7,105 | £3.65 a week | Optional, protects NI record and contributory benefits |
Source: HMRC, Rates and thresholds for employers 2026 to 2027. Figures shown are for standard Category A employees; other category letters (apprentices, under-21s, veterans) use different rates.
How Employee National Insurance Works
If you’re employed, you pay Class 1 National Insurance through PAYE. You pay nothing on earnings up to the Primary Threshold (£12,570 a year, £1,048 a month, or £242 a week for 2026/27), 8% on earnings between the Primary Threshold and the Upper Earnings Limit (£50,270 a year, £4,189 a month, or £967 a week), and 2% on anything above that. Unlike Income Tax, National Insurance is worked out separately for each pay period rather than cumulatively across the year, which is why this calculator lets you choose weekly, fortnightly, 4-weekly, monthly, or annual pay frequencies, using the relevant HMRC pay-period thresholds. Each band’s Class 1 contribution is rounded to the nearest penny, with an exact half-penny rounded down, following HMRC’s exact percentage method.
How Self-Employed National Insurance Works
If you’re self-employed, you pay Class 4 National Insurance on your taxable trading profit, at 6% between £12,570 and £50,270, then 2% above that, collected through Self Assessment alongside Income Tax. Compulsory Class 2 National Insurance was abolished from April 2024. If your profits are at or above the Small Profits Threshold (£7,105 for 2026/27), you’re treated as having paid Class 2 automatically, protecting your National Insurance record and entitlement to contributory benefits, including the State Pension, at no extra cost. Below that threshold, Class 2 becomes voluntary at £3.65 a week if you want to keep building qualifying years. This calculation is for standard self-employed trading profits and doesn’t cover special Class 4 rules that can apply to certain occupations or circumstances — check with HMRC or an adviser if you think a special rule might apply to you.
National Insurance vs Income Tax
National Insurance and Income Tax are separate charges collected alongside each other, but they work differently. Income Tax is cumulative across the tax year and uses a Personal Allowance and tax bands. National Insurance for employees is calculated fresh for each pay period using that period’s own threshold, and doesn’t use a Personal Allowance in the same way. This calculator covers National Insurance only — for a combined view of Income Tax and National Insurance together, see our Income Tax Calculator.
Frequently Asked Questions
What National Insurance category does this calculator use?
This calculator uses standard Category A rates, which apply to most employees. Other category letters give reduced or different rates for groups such as apprentices under 25, employees under 21, and veterans in their first year back in civilian work. If you’re not sure which category applies to you, check your payslip.
Why does National Insurance ask for a pay frequency, when Income Tax doesn’t work that way?
Income Tax under PAYE is cumulative: it looks at your total pay and tax paid so far in the year. National Insurance is different — it’s calculated separately for each pay period, using that period’s own threshold, with no year-to-date carry-over. That’s why this calculator lets you choose weekly, fortnightly, 4-weekly, monthly, or annual, using the relevant HMRC pay-period thresholds, rather than assuming one figure is simply the other divided or multiplied.
What does the “Annualised NI” figure mean?
It’s the total you’d pay over a year if this exact pay amount repeated every pay period, unchanged, for the whole 12 months. It can differ from what you’d get by entering the equivalent annual salary directly using the Annual option, because National Insurance thresholds are applied separately to each pay period rather than to your salary as a whole. If your real pay varies — for example with overtime, bonuses, or a pay rise partway through the year — your actual annual total will differ from this estimate too, since each period’s National Insurance depends only on that period’s own pay.
What’s the difference between Class 1, Class 2 and Class 4 National Insurance?
Class 1 employee National Insurance is deducted from employees’ pay through PAYE. Employers also pay a separate Class 1 National Insurance contribution on employees’ earnings. Class 4 is paid by the self-employed on trading profits, through Self Assessment. Class 2 used to be a flat weekly charge for the self-employed, but compulsory Class 2 was abolished from April 2024; it now only exists as a voluntary contribution for self-employed people with profits below the Small Profits Threshold who want to protect their National Insurance record and entitlement to contributory benefits, including the State Pension.
Do I still need to pay Class 2 National Insurance?
Not compulsorily. If your self-employed profits are at or above the Small Profits Threshold (£7,105 for 2026/27), you’re treated as having paid Class 2 automatically, with no separate payment needed, and it still counts towards your National Insurance record and entitlement to contributory benefits, including the State Pension. If your profits are below that threshold, Class 2 is voluntary at £3.65 a week; paying it helps protect that same record and entitlement, but doing so is optional.
Does this calculator include employer National Insurance?
No, this calculator shows the National Insurance you pay personally as an employee or as a self-employed person. It doesn’t calculate the separate Class 1 National Insurance an employer pays on top of your salary, which uses different rates and thresholds.
Does this calculator include Income Tax?
No, this is a National Insurance calculator only. The “Pay After NI” and “Profit After Class 4 NI” figures shown have not had Income Tax deducted. For a combined estimate of Income Tax and National Insurance together, use our Income Tax Calculator.
What’s the difference between this and the Income Tax Calculator?
The Income Tax Calculator gives a combined view of Income Tax and National Insurance together, including take-home pay, tax bands, pension relief and Marriage Allowance. This calculator focuses specifically on National Insurance, including a full band-by-band breakdown and, on the Self-Employed tab, the voluntary Class 2 position that the Income Tax Calculator doesn’t cover in the same detail. Either can be used depending on what you want to check.