National Insurance Calculator UK

What This Calculator Estimates

National Insurance in the UK is a separate payroll contribution from Income Tax, funding state benefits like the State Pension and certain unemployment and health benefits, calculated using its own threshold structure that differs from Income Tax bands. Because employees, employers, and the self-employed pay different classes of National Insurance at different rates, this calculator uses an editable rate so you can model the specific class and rate relevant to your situation.

How to Use This Calculator

  1. Enter annual gross salary.
  2. Enter an estimated NI rate.
  3. Click Estimate National Insurance.
  4. Review the annual and monthly NI estimate.
  5. Verify official UK rules before relying on the result.

2026/27 UK National Insurance Rates

Employees pay Class 1 NI at 0% on earnings up to the Primary Threshold of £12,570/year, then 8% on earnings between £12,570 and the Upper Earnings Limit of £50,270, dropping to 2% on anything above that. Employers pay a separate 15% on earnings above a £5,000 secondary threshold, with no upper cap. Self-employed profits are charged Class 4 NI at 6% between £12,570 and £50,270, then 2% above — Class 2 was abolished in April 2024, though voluntary £3.65/week payments can still protect your State Pension record if profits are low.

Related Calculators

Salary Calculator UK · Income Tax Calculator UK · Payroll Tax Calculator

Tips for a More Accurate Estimate

Frequently Asked Questions

Is National Insurance the same as Income Tax?

No, they're separate systems — Income Tax funds general government spending while National Insurance specifically funds state benefits and pension entitlement, using its own thresholds.

Do employees and self-employed people pay the same National Insurance?

No, employees typically pay Class 1 National Insurance, while the self-employed pay Class 2 and/or Class 4 depending on profit levels — rates and thresholds differ between these classes.

Does National Insurance affect my State Pension?

Yes, your National Insurance contribution record (measured in qualifying years) determines your eligibility for and amount of the UK State Pension.

Does this calculator apply the correct NI class automatically?

No, enter the rate applicable to your specific NI class (employee, employer, or self-employed) for an accurate estimate.

Where can I confirm current official NI rates and thresholds?

HMRC publishes current National Insurance thresholds and rates by class on its official website.

This calculator provides UK National Insurance estimates only. Official thresholds, classes, and rates can change, so verify current rules before relying on the result.

Last updated: May 11, 2026

About the National Insurance Calculator UK

Free National Insurance Calculator UK — This calculator estimates UK National Insurance from the salary and NI rate you enter. It is intended for simple. National Insurance Calculator UK is built for one job — turning your inputs into an accurate result without spreadsheets, apps, or guesswork.

You'll enter Annual Gross Salary and Estimated NI Rate, and the calculator handles the rest.

How to Use It

The process takes under a minute:

  1. Enter annual gross salary.
  2. Add estimated ni rate.
  3. Review the result — adjust any field to see it update live.

Who This Is For

Whether you're comparing a few scenarios or just need one clean answer, this calculator is meant to save you the manual work.

This page also answers common questions like "Is National Insurance the same as Income Tax?" and "Where can I confirm current official NI rates and thresholds?" — see the FAQ section above for details.

Good to Know

Will it work on my phone? Yes, the page is fully responsive and works the same on mobile, tablet, or desktop.

Does it store my information? No. The calculation happens in your browser and nothing you enter is saved or sent anywhere.

How accurate is this? The math behind this tool follows established, conventional methods — if a result looks off, the most likely cause is an input worth rechecking.

A Note on Precision

Small changes in your inputs can shift the result more than you'd expect, so it's worth running the numbers more than once if you're using this for something important. Treat the output as a strong estimate built on the figures you provide, not a substitute for professional advice where real money or decisions are on the line.

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Zaculators has 250+ free calculators spanning finance, business, health, tax, and everyday planning. Browse the full calculator directory if National Insurance UK isn't quite the tool you're after.