Comparing UK Take-Home Pay Calculators: Feature Coverage and Modelling Differences (2025/26)

Executive Summary

• Most UK take-home pay calculators produce consistent results for straightforward PAYE scenarios with no pension or student loan inputs.
• Pension modelling is the primary source of divergence. Calculators differ in whether they support NET pay, relief at source, or salary sacrifice — and some mislabel the mechanism they implement.
• Salary sacrifice support is not universal. Where it is supported, it materially affects National Insurance and student loan calculations.
• Student loan plan coverage varies. Plan 5 and Postgraduate loan support is inconsistent across tools.
• Tax code input is widely offered but rarely validated — several calculators accept invalid codes without warning.
• Capital gains tax is not supported by any of the calculators reviewed.
• Access models differ. Some tools display ads or newsletter signup prompts that interrupt the calculation flow, though none require account creation.

Methodology

Inclusion Criteria

Calculators were included if they met all of the following:

• Web-based (accessible via a browser, no install required)
• No login or account creation required to access full modelling
• UK-focused, covering at least England/Wales income tax and National Insurance

One additional calculator was investigated but excluded from the feature assessment: Pie Tax (UK Taxed Interest). The web interface presents what appears to be an online calculator, but on submission it redirects to app store download links and prompts for account creation. No results are displayed in the browser, so the tool could not be assessed beyond the initial input screen.

Feature Assessment

Each calculator was assessed against a structured feature matrix covering five categories:

1. Core Features — tax bands, NI, period toggles, tax year selection
2. Income Inputs — salary types, overtime, bonus, self-employment
3. Pension Modelling — input types, mechanism (NET pay, relief at source, salary sacrifice), employer contributions
4. Student Loans — plan coverage (1, 2, 4, 5, Postgraduate)
5. Transparency and UX — component breakdowns, effective/marginal rates, assumptions, access model

Status Taxonomy

Each feature was classified using the following statuses:

Calculators Reviewed

Seven calculators were assessed:

1. Money Saving Expert — MoneySavingExpert.com, consumer finance advice site founded by Martin Lewis
2. HMRC — official UK government tax calculator operated by HM Revenue & Customs
3. The Salary Calculator — independent UK salary calculator run by Goodcalculators Ltd
4. UK Tax Calculators — independent tax calculation site covering personal and business tax
5. Listen to Taxman — independent UK salary and tax calculator (referred to as “UK Salary Calculator” in tables)
6. ANNA Money — business banking provider offering a free income tax calculator
7. Take-Home Calculator — take-home pay calculator by Casomo Ltd
8. Pie Tax — tax filing app by Pie Technologies Ltd (excluded — redirects to app store on submission, no browser results)

Feature Matrix Summary

Core Features

All seven calculators support UK income tax bands, National Insurance, and monthly vs annual toggling. Scottish tax band support is present across all tools, though ANNA’s calculator does not make this explicit in the interface.

Tax year selection is available in six of seven calculators. HMRC’s tool does not offer tax year selection and operates on the current year only.

Income Inputs

Annual salary input is universal. Monthly salary input is absent from The Salary Calculator. Hourly rate input is supported by six of seven calculators, with ANNA’s being the exception.

Overtime and bonus inputs are rare. The Salary Calculator and Take-Home Calculator support overtime. Bonus input is available in The Salary Calculator, UK Tax Calculators, and Take-Home Calculator.

No calculator reviewed supports multiple income streams or dividend income.

Pension Modelling

Pension modelling is where the most significant divergence appears.

Percentage input is supported by MSE, HMRC, ANNA, and Take-Home Calculator. The Salary Calculator offers a percentage input but appears to interpret the value as a fixed amount — behaviour inconsistent with the labelled input type.

NET pay behaviour is observed in MSE and HMRC. The Salary Calculator, UK Salary Calculator, and Take-Home Calculator each label their pension option as "auto enrolment"but exhibit NET pay behaviour without explicitly stating the mechanism. ANNA deducts pension from take-home pay only, without altering taxable income — behaviour inconsistent with any standard pension mechanism.

Relief at source is supported by HMRC, The Salary Calculator, and Take-Home Calculator.

Salary sacrifice is supported explicitly by The Salary Calculator and Take-Home Calculator. UK Tax Calculators appears to exhibit salary sacrifice behaviour but does not label it as such.

Employer contributions are only modelled by The Salary Calculator.

Student Loans

Plans 1, 2, and 4 are supported by all seven calculators. However, The Salary Calculator allows multiple undergraduate plans to be selected simultaneously — behaviour that does not reflect how student loan repayments work in practice. See the GOV.UK guide to repayment plans for details on which plan applies.

Plan 5 support is inconsistent: it is available in UK Tax Calculators, UK Salary Calculator, Take-Home Calculator, and The Salary Calculator (with the same multi-select issue). MSE, HMRC, and ANNA do not include Plan 5.

Postgraduate loan support follows a similar pattern, absent from MSE and HMRC.

Additional Interactions

Tax code input is offered by six of seven calculators. Of these, four (MSE, The Salary Calculator, UK Tax Calculators, and UK Salary Calculator) accept invalid tax codes without validation. HMRC, ANNA, and Take-Home Calculator validate input.

Marriage allowance is supported by The Salary Calculator, UK Tax Calculators, and UK Salary Calculator. Blind person’s allowance follows a similar distribution, with MSE also supporting it.

Capital gains tax is not supported by any calculator reviewed.

Transparency and UX

Component breakdowns (showing tax, NI, and student loan as separate line items) are available in six of seven calculators. ANNA does not provide a component breakdown.

Effective tax rate display is available in UK Salary Calculator and Take-Home Calculator. Take-Home Calculator is the only tool that displays the marginal rate.

Documented assumptions are present in HMRC, UK Tax Calculators, and Take-Home Calculator. No calculator displays a "last updated" date.

Calculation Accuracy

To test whether calculators produce consistent results, four standardised cases were run across all seven tools. Each case isolates a specific modelling dimension — baseline PAYE, personal allowance taper, salary sacrifice, and capital gains tax.

Test Cases

Case A — Baseline PAYE

A straightforward scenario: £45,000 gross salary with 5% NET pay pension and Plan 2 student loan. HMRC and UK Tax Calculators could not be tested as neither supports NET pay pension input.

Of the five calculators that produced results, MSE reported £33,207 while the others clustered around £32,632–£32,634 — a spread of approximately £575. The divergence is in the tax figure: MSE calculated £5,462 in income tax versus £6,034–£6,036 from the others. NI figures were consistent across all five.

ANNA produced a lower pension deduction (£1,938 versus the expected £2,250), suggesting its percentage input did not correctly calculate 5% of the gross salary.

Case B — Personal Allowance Taper

At £110,000 gross with 10% NET pay pension, this case tests whether calculators correctly apply the personal allowance taper (which removes £1 of allowance for every £2 earned above £100,000).

MSE, The Salary Calculator, and Take-Home Calculator all reported £67,757 with tax of £27,032. UK Salary Calculator produced £67,761 with tax of £27,028 — a spread of just £4 across all four supported calculators.

ANNA exhibited a significant pension modelling anomaly: the pension contribution was capped at £4,403 rather than the expected £11,000 (10% of gross). This also distorted the tax figure (£33,432 versus £27,028–£27,032 from other tools).

Case C — Salary Sacrifice

At £135,000 with a £20,000 salary sacrifice pension and Plan 2 student loan, this case tests the most complex modelling scenario. Only four calculators support salary sacrifice: HMRC, The Salary Calculator, UK Tax Calculators, and Take-Home Calculator.

Tax figures were consistent at £36,432 across all four. However, NI and student loan figures diverged. HMRC reported £4,711 in NI versus £4,310–£4,311 from the others, and £9,587–£9,588 in student loan repayments versus £7,704–£7,788 from The Salary Calculator and UK Tax Calculators. The higher HMRC figures are likely because HMRC only supports percentage pension input — 14.81% was entered as an approximation of £20,000, which may have produced a slightly different pre-NI gross figure.

HMRC also reported a pension deduction of £19,993 rather than the target £20,000, consistent with the percentage approximation.

Case D — Capital Gains Tax

None of the seven calculators reviewed support capital gains tax modelling. This case could not be assessed.

Key Findings

1. Straightforward PAYE alignment. For a simple gross salary with no pension, student loan, or non-standard tax code, most calculators produce consistent results. The arithmetic for basic income tax and NI is well-established and broadly implemented correctly.
2. Pension mechanism is the primary divergence point. The distinction between NET pay, relief at source, and salary sacrifice is not consistently implemented or labelled. Some calculators deduct pension from take-home pay without altering the taxable income calculation — a behaviour that does not correspond to any standard HMRC pension mechanism.
3. Mislabelling is more common than arithmetic error. Where results diverge, the cause is more often a mismatch between what a feature is labelled and how it behaves than a straightforward calculation mistake. This is particularly evident in pension and student loan modelling.
4. Salary sacrifice materially affects downstream calculations. When salary sacrifice is correctly implemented, it reduces gross pay before NI and student loan thresholds are applied. Calculators that do not model this mechanism produce higher NI and student loan deductions for the same pension contribution.
5. Student loan plan coverage is inconsistent. Plan 5 (post-2023 English/Welsh undergraduate loans) and Postgraduate loans are not universally supported.
6. Tax code validation is widely absent. Most calculators that accept custom tax codes do not validate the input format. This can produce silently incorrect results if a user enters an invalid code.
7. Transparency varies significantly. Only three calculators document their assumptions. No calculator displays a last-updated date, making it difficult for users to verify whether the tool reflects the current year’s rates.
8. Access models differ. Several calculators display ads or newsletter signup prompts that interrupt the calculation flow. None of the calculators reviewed require account creation to access results.

Data and Methodology Notes

• Tax year tested: 2025/26
• Assessment date: March 2026
• Full feature matrix: view on Google Sheets
• Version: 1.1

This comparison reflects the state of each calculator at the time of testing. Features and behaviours may change as calculators are updated.