How to Calculate National Insurance
What is National Insurance?
National Insurance (NI) is a UK government contribution that funds the state pension, NHS, and other benefits. Employees pay Class 1 NI on their earnings; employers also pay Class 1 NI on each employee's wages. Self-employed workers pay Class 2 and Class 4 NI instead.
Step-by-Step Guide
- 1Employee Class 1 NI 2024/25: 8% on £12,570–£50,270, then 2% above
- 2Employer Class 1 NI: 13.8% on earnings above £9,100 (secondary threshold)
- 3Both employee and employer NI fund state benefits separately from income tax
- 4NI contributions count toward state pension eligibility (35 years required for full pension)
Worked Examples
Frequently Asked Questions
What is National Insurance?
National Insurance (NI) is a UK government contribution that funds the state pension, NHS, and other benefits. Employees pay Class 1 NI on their earnings; employers also pay Class 1 NI on each employee\
How accurate is the National Insurance calculator?
The calculator uses the standard published formula for national insurance. Results are accurate to the precision of the inputs you provide. For financial, medical, or legal decisions, always verify with a qualified professional.
What units does the National Insurance calculator use?
This calculator works with inches, British pounds, percentages. You can enter values in the units shown — the calculator handles all conversions internally.
What formula does the National Insurance calculator use?
The calculator applies the standard formula for this type of calculation. See the 'How It Works' steps above for the detailed formula breakdown.
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