Useful next calculations
Rates and sources
UK tax rates and thresholds, as published by HMRC. Scotland and Wales have devolved rates for income tax and property transactions.
Source: HMRC — Tax rates. Check the linked guidance and any live quote before acting.
When to use this calculator
- Before accepting a pay change, bonus, pension contribution or salary-sacrifice option.
- When you want a simple take-home estimate before payroll or filing.
- When you are approaching the £100,000 income level and want to see the personal allowance taper.
- When you need to convert between hourly, monthly and annual pay.
A worked example
These are the example figures the calculator opens with.
| Input | Value |
|---|---|
| Gross Annual Salary (£) | £45,000 |
| Monthly Sacrifice Amount (£) | £300 |
| Income Tax Rate (%) | 40% |
| National Insurance Rate (%) | 8% |
For those figures the calculator returns:
- Annual saving: £1,728.00
- Tax saving: £1,440.00
- NI saving: £288.00
- Net monthly cost: £156.00
How to read your results
Annual Saving
The recurring yearly benefit of the change or upgrade under the assumptions you entered.
Tax Saving
Review this figure alongside your gross income so you can understand deductions before the tax year closes. It is a planning estimate, not a filed return.
Method & assumptions
This scenario calculator multiplies the annual sacrifice amount by the Income Tax and employee National Insurance rates you enter. It does not calculate progressive bands, employer National Insurance, pension allowance limits or benefit-in-kind tax automatically.
Use the marginal rates that apply to the slice of salary being sacrificed and check that pay remains within scheme and National Minimum Wage rules. Benefits, statutory pay, mortgage applications and pension contributions can be affected, so confirm an election with the employer's payroll or benefits team.
Common mistakes
- Entering gross income when you really want take-home pay, or vice versa.
- Ignoring pension contributions, deductions or local tax rules that change the result.
- Comparing monthly and annual figures without standardising them first.
- Overlooking National Insurance or student-loan plan differences that apply to you.
What to do next
- Check the same scenario with related pay or deduction calculators.
- Keep a copy of the assumptions so you can compare the next tax year or pay period.
- If you are self-employed, compare this result with the self-employment tax calculator.
- Check whether a small pension contribution change moves take-home pay more than you expect.