Salary Sacrifice Calculator UK 2026

Our Salary Sacrifice Calculator compares paying your pension contribution through salary sacrifice against a standard relief-at-source contribution, so you can see exactly where any difference in take-home pay comes from. Enter your salary, your contribution and how much (if any) of the employer National Insurance saving your employer passes back into your pension, and the calculator breaks down Income Tax, National Insurance, student loan repayments and take-home pay side by side.

What Is Salary Sacrifice?

Salary sacrifice (sometimes called salary exchange) is a formal agreement with your employer to give up part of your contractual salary in exchange for a non-cash benefit – most commonly, an employer pension contribution. Because your official gross salary is reduced, you pay less Income Tax and employee National Insurance, and your employer pays less employer National Insurance too.

This is different from a standard (relief-at-source) pension contribution, where your gross salary is unchanged: you pay your contribution from your net (after-tax) pay, and your pension provider claims 20% basic-rate tax relief from HMRC automatically. If you pay higher or additional-rate tax, the extra relief above 20% is not usually applied automatically at source – it typically needs to be claimed through your tax code or a Self Assessment return.

Salary Sacrifice vs Standard Contribution: Where the Difference Comes From

A common misconception is that salary sacrifice simply “gives you free money.” It does not. Once any entitled higher-rate tax relief is properly reclaimed, the Income Tax treatment of a salary sacrifice contribution and a standard contribution works out broadly the same. The genuine, reliable advantage of salary sacrifice is National Insurance:

• Employee NI: because your contractual salary is reduced before NI is calculated, you avoid paying employee NI (8% or 2%, depending on where your income falls) on the sacrificed amount. A standard contribution does not reduce your NI-able earnings at all.
• Employer NI: your employer also avoids paying 15% employer NI on the sacrificed amount. Some employers choose to add some or all of this saving back into your pension – many do not. This calculator lets you model both.
• Student loan repayments: if you have a student loan, salary sacrifice can also reduce your repayments, because they are calculated on your (now lower) contractual salary. A standard relief-at-source contribution does not reduce student loan repayments, because they are based on gross pay before any personal pension contribution.

Worked Example

Take someone earning £35,000 a year who contributes 5% of salary (£1,750) to their pension, with National Insurance Category A and no student loan, in the 2026/27 tax year:

In this example the employee ends up roughly £140 a year better off in take-home pay under salary sacrifice than under a standard contribution, purely from the employee National Insurance saving – for the same £1,750 reaching the pension. If the employer also passes back some of their own NI saving, the pension pot itself grows faster too.

How Employer National Insurance Works

When you sacrifice salary, your employer’s National Insurance bill falls too – typically by 15% of the sacrificed amount (above the secondary threshold). Crucially, this saving belongs to your employer, not automatically to you. Some employers pass on all of it, some pass on a portion, and many keep it entirely as a cost saving for the business. This calculator clearly separates “Employer NI Saved” (the total saving your employer makes) from “Employer NI Added to Your Pension” (the amount that actually reaches your pot), because they are frequently not the same figure. Always check your employer’s salary sacrifice scheme rules to find out their policy.

How Student Loans Are Affected

Student loan repayments are calculated on your gross pay above the relevant plan threshold. Because salary sacrifice reduces your contractual gross pay, it can genuinely reduce your monthly student loan repayment – on top of the NI saving. A standard relief-at-source pension contribution does not have this effect, since it is paid from your net pay and does not touch your gross salary figure used for the student loan calculation. This calculator supports Plan 1, Plan 2, Plan 4, Plan 5 and Postgraduate Loan repayment thresholds.

Limitations of This Calculator

• It uses rest-of-UK (England, Wales and Northern Ireland) Income Tax bands, not the separate Scottish Income Tax bands.
• It assumes any higher or additional-rate tax relief on a standard relief-at-source contribution is claimed in full through your tax code or Self Assessment. If you never reclaim this, your real-world standard-contribution take-home pay will be lower than shown here.
• It does not model the Annual Allowance or tapered Annual Allowance for pension contributions, which can restrict how much tax-relieved pension contribution you can make if your income is very high.
• It does not model other salary sacrifice benefits such as cycle to work schemes, ultra-low emission company cars, or technology schemes – only pension contributions.
• Reducing your contractual salary through salary sacrifice can, in some circumstances, affect entitlement to salary-linked benefits, mortgage affordability assessments, and statutory payments (such as Statutory Maternity Pay, which is based on average earnings). This calculator flags a warning if your adjusted salary falls near the Lower Earnings Limit, but you should always check the impact with your employer or a financial adviser before agreeing to a significant sacrifice.
• This tool provides a planning estimate only. It is not financial, tax or legal advice.

Frequently Asked Questions