How We Calculate
The method, the sources, and the assumptions that sit behind every number.
Where the Data Comes From
Every rate on NetSalaryTax comes straight from each country's official tax authority. There are no estimates, no third-party compilations and no crowd-sourced figures. Each JSON data file carries a direct link to the official source it was taken from.
Those sources are reviewed and refreshed as each tax year opens, and straight away whenever a government announces a change part-way through the year.
What Each Calculation Covers
The figures account for the standard deductions any employee runs into:
- Income tax, including the progressive bands and any personal allowance or basic deduction
- Social insurance or National Insurance, the employee share paid into state pension, unemployment and health funds
- Solidarity surcharges where they apply, as in Germany
- Medicare and health levies where they apply, as in Australia and the US
What It Leaves Out
A few deductions swing too much from person to person to apply by default:
- Workplace pension contributions (varies by employer and employee choice)
- Student loan repayments (varies by plan and country)
- State and local income taxes in the US (varies by state)
- Provincial income tax in Canada (varies by province)
- Cantonal and communal taxes in Switzerland (varies by canton)
- Church tax in Germany and Austria (optional)
- Benefits-in-kind (company car, private medical, etc.)
- Tax reliefs and credits specific to individual circumstances
Because of these, your real take-home may sit a little above or below our estimate. What we show is a standard full-time employee carrying only the universal deductions, with no special reliefs layered on.
How the Maths Works
Income tax is worked out with each country's official progressive-band method. For every band we take the tax due on the slice of income that falls inside it, then add those slices together across all the bands that apply.
Take the UK as an example, on 2026/27 rates:
- First £12,570: £0 (Personal Allowance)
- £12,571-£50,270: taxed at 20%
- £50,271-£125,140: taxed at 40%
- Above £125,140: taxed at 45%
National Insurance and other social contributions are handled on their own, each with its own thresholds and rates.
A handful of countries, Germany among them, use a continuous mathematical formula rather than fixed bands. For those we approximate with band averages, flag it on the relevant calculator, and stay within roughly 1% to 3% of the exact figure at most income levels.
Effective Rate vs Marginal Rate
Effective rate: total tax paid as a percentage of gross income. It is the average across everything you earn.
Marginal rate: the rate that hits the next pound, dollar or euro you earn. This is the one to watch when you are weighing up extra hours or a pay rise.
How Often We Update
- Yearly: all 22 countries are reviewed as their own tax year begins.
- On short notice: mid-year changes from budgets or emergency legislation are applied within 48 hours of being published.
- Corrections: confirmed errors that readers report are fixed within 48 hours.
Each data file carries a lastUpdated and a nextReview date, both visible in the admin panel and readable from the JSON files at /data/tax-rates/[country].json.
A Note of Caution
Everything here is an estimate for general information, not financial or tax advice. Before you act on a number, check it against the official source or run it past a qualified tax professional.
Spotted a mistake? Tell us, and please include the country, the wrong value and a link to the official source. We do take accuracy seriously.