Continue your plan
Useful next calculations
Rates & sources2026/27
2026/27 Income Tax and Class 4 NI reserve estimate. Payments on account are shown as advance cash requirements and are not added to the tax liability.
| Band / figure | Rate |
|---|---|
| Class 4 main rate | 6% |
| Class 4 additional rate | 2% |
| Payment-on-account instalments | normally 50% each |
| Normal due dates | 31 January / 31 July |
Source: HMRC — self-employed National Insurance — source checked for 2026/27.
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 realistic UK planning example
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
| Input | Value |
|---|---|
| Forecast taxable self-employed profit (£) | 50000 |
| Other non-savings taxable income (£) | £35,000 |
| Gross pension contributions + grossed-up Gift Aid (£) | £35,000 |
| Income Tax already deducted at source (£) | £35,000 |
After entering these figures, review estimated income tax, estimated class 4 ni and current-year self assessment amount after tax deducted together rather than in isolation. Then rerun the tool with one input adjusted.
How to read your results
Estimated Income Tax
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.
Estimated Class 4 NI
The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.
Current-Year Self Assessment Amount After Tax Deducted
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.
Remaining Balancing Payment
The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.
Each Modelled Payment on Account
The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.
January Cash Target
The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.
July Cash Target
The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.
Monthly Current-Year Reserve
The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.
Reserve as Share of Profit
The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.
Method & assumptionsAuthoritative sources
This planner estimates 2026/27 Income Tax on the profit and other non-savings income entered, then adds Class 4 National Insurance when selected and subtracts tax already deducted at source. Payments on account already made reduce the remaining balancing payment.
The monthly reserve covers the estimated current-year Self Assessment amount. When payments on account are selected, the January cash target adds one half of that amount as a proxy for the next year's first payment; the July target shows the second half. Those advances are not counted as extra tax.
HMRC uses the filed previous-year return and detailed relevant-amount rules. This estimate excludes VAT, student loans, CGT, HICBC, Class 2 choices, penalties, interest and many reliefs. Use the HMRC statement and reduce payments on account only when there is a reasonable basis, because an excessive reduction can attract interest.
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.
Frequently asked
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