National Insurance Calculator

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\

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.

This calculator works with inches, British pounds, percentages. You can enter values in the units shown — the calculator handles all conversions internally.

The calculator applies the standard formula for this type of calculation. See the 'How It Works' steps above for the detailed formula breakdown.