National Insurance Calculator

Work out national insurance instantly with clear inputs, formula shown and shareable results.

About National Insurance Calculator

Contributions are banded: nothing below the lower threshold, a main rate between the thresholds, and a much lower rate above the upper limit. That structure makes the effective rate fall as pay rises beyond the upper limit.

Formula

Banded contributions

Contribution = (min(pay, UEL) - threshold)×main rate + (pay - UEL)×2%

Worked example

With the default values below, National Insurance Calculator returns Annual Contribution of $2,994.40. Change any input above and every figure here is recalculated in your browser.

Inputs used

Annual Salaryminimum 0: 50,000
Lower Earnings Thresholdminimum 0: 12,570
Upper Earnings Limitminimum 0: 50,270
Main Contribution Rateaccepts 0–20 %: 8 %

Results

Annual Contribution: $2,994.40
Contribution On The Main Band: $2,994.40
Contribution Above The Upper Limit: $0.00
Effective Rate On Total Pay: 5.989%

Step by step

1Values used
2Banded contributions
3Annual Contribution= 2,994.40
4Contribution On The Main Band= 2,994.40
5Contribution Above The Upper Limit= 0.00
6Effective Rate On Total Pay= 5.989

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or fees or charges into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Tax figures are estimates based on the rates, caps and thresholds you enter. Real rules differ by jurisdiction and change every year, and personal circumstances alter the outcome. This is not tax or financial advice — confirm with a qualified adviser.
This is an estimate for general information and not professional financial, tax or legal advice. See the full disclaimer for the limits that apply to this kind of calculator.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Tax figures are estimates based on the rates, caps and thresholds you enter. Real rules differ by jurisdiction and change every year, and personal circumstances alter the outcome. This is not tax or financial advice — confirm with a qualified adviser.

Frequently Asked Questions

Why does the rate drop above the upper limit?

Because contributory benefits are capped, so contributions above that level buy no additional entitlement.

Is it charged on all income?

No — only on earnings from employment or self-employment, not on investment income.