Pay Gap Calculator

45,000 vs 55,000: 22.2% pay gap = 10,000/year. Over 20 working years, cumulative gap 200,000 — material difference from a single promotion or negotiation.

Run it with sensible defaults

Using salary a of 45,000, salary b of 55,000, years remaining of 20, the calculation works out to 22.22%. The defaults are meant as a starting point, not a recommendation.

The levers in this calculation

The inputs — Salary A, Salary B, and Years Remaining — do not pull with equal force. Not every input has equal weight. Adjusting one input at a time toward extreme values shows which ones move the result most.

How the math works

Percentage difference from lower salary.

Using this in pay negotiations

Knowing the exact figure behind a headline rate gives you specific numbers to anchor to in conversations about pay. "The difference is £X per month after tax" lands harder than "a couple of grand a year". Concrete numbers move decisions.

What this doesn't capture

Tax bands, pension contributions, student-loan deductions, and benefits-in-kind sit outside this calculation. The figure is the headline; your actual position depends on local tax rules and personal circumstances. Pair with a dedicated take-home calculator for the full picture.

Related calculations worth running

Plans get firmer when you triangulate. Alongside this one, the raise negotiation calculator, the commission vs base tradeoff calculator, and the two income household gap calculator tend to come up in the same conversations. Running two or three together exposes inconsistencies in any single assumption — which is usually where the useful insight lives.

Worked example

Two candidates are offered positions at the same firm. Candidate A accepts an offer of 48,000 per year. Candidate B negotiates to 54,000. The gap is 6,000 annually, or 12.5% above the lower figure. If both work for the next 25 years without further change to either salary, the cumulative gap reaches 150,000 in headline earnings alone. This does not account for compounding effects if either party receives raises, nor tax treatment or benefits.

When this metric matters

Pay gaps surface in several contexts:

• Salary negotiation — understanding the real-world annual and lifetime cost of accepting a lower offer
• Promotion decisions — quantifying the financial impact of stepping into a higher-paid role
• Career transitions — comparing earnings between industries or job types
• Equity audits — internal analysis of salary differences across teams or levels
• Budget planning — forecasting income differences when household income composition changes

What this calculates and what it does not

This calculator estimates: The percentage difference between two salary figures and the total accumulated difference if that gap remains constant over a given number of years.

This calculator does not estimate: Actual take-home pay (tax-adjusted); the effect of raises, bonuses, or inflation on either salary; pension or benefits contributions; changes in earning power over time; or the cost of living in different locations. The result is an illustration based on static inputs and does not model real career progression.

For educational illustration

This calculator shows estimated outcomes based on the numbers you enter. Results are for illustration and planning purposes. Real-world pay outcomes depend on factors outside this tool — individual circumstances, local regulation, and contractual terms all shape what an earnings gap means in practice.