Methodology and accuracy

Data source

The sole data source is the tax calculator of the Federal Tax Administration (FTA, swisstaxcalculator.estv.admin.ch) for tax year 2026. It contains the tariffs of all cantons, the tax multipliers of all 2’110 municipalities, the church tax multipliers, the personal taxes, the wealth tax tariffs and the deduction rules. The data was retrieved automatically on 3 October 2026.

The FTA provides the same basic data (tax multipliers, tariffs, deductions) for export on the calculator’s “Retrieve basic data” page. These official exports are kept on file and compared with the data used here on every test run: the tax multipliers of all municipalities are identical, the splitting divisors match, and the bracket tariffs coincide at every bracket boundary; the bracket tariffs of 24 series are taken directly from the official export.

How the tariffs are derived

The FTA tax calculator shows the “simple tax” for any taxable income. For each canton, it is queried for single and married persons over a dense income grid (every CHF 1’000 up to 300’000, then more coarsely up to 3 million). Wherever the slope changes, the bracket boundary is determined to within CHF 100. This yields reference-point tables, with the tariff linearly interpolated between the reference points; for bracket tariffs this is exact, for formula tariffs (Basel-Landschaft, Fribourg, Ticino, Valais) the deviation is below one franc. Maximum rates (such as 5.7 % in Lucerne) and formula curves above CHF 1 million are thus also covered.

The wealth tax tariffs and the deductions are collected in the same way: for each canton, each household type (single, married with one or two incomes) and zero to three children, the taxable income is queried for 42 gross incomes between 0 and CHF 1 million, refined to a CHF 500 grid at kinks, determined to within CHF 1 at jumps (steps of social deductions) and linearly interpolated in between. The age-dependent BVG contributions are calculated exactly according to the FTA tax calculator’s model; under age 25, its assumption of no BVG savings contributions with the higher insurance deduction “without contributions” applies.

In Schwyz (relief deduction) and Bern (deduction for modest incomes), taxable income also depends on wealth. These deductions were modelled for each household type (Schwyz: 30 % of the difference from the income threshold minus 3 % of net wealth; Bern: one tenth of taxable wealth counts towards the relevant income, and the deduction decreases by CHF 150 per person for every CHF 2’000) and verified against the FTA tax calculator. All other cantons were checked for such a dependency – none was found.

Calculation steps

1. Gross income per person → minus OASI/DI/IC (AHV/IV/EO), unemployment insurance (ALV), non-occupational accident insurance (NBU), occupational pension (BVG) → net salary.
2. Net salary → minus professional expenses, insurance deduction, social deductions (married persons, two-earner couples, children, others depending on the canton) → taxable income (canton and federal).
3. Taxable income (rounded down to CHF 100) → tariff → simple tax. Married persons and single persons with children receive the tariff for married persons; for splitting and family quotient, the rate-determining income is used exactly or rounded down to CHF 100, depending on the canton, as in the FTA tax calculator.
4. Simple tax × cantonal tax multiplier, × municipal tax multiplier, × church tax multiplier. Cantonal special rules: Geneva (12 % reduction, 1 additional centime), Vaud (rebate on the cantonal coefficient, cap at 30 % of taxable income), Valais (deduction from the tax amount for married persons, minimum tax, municipal scales), Basel-Landschaft (reduction per child), Neuchâtel (deduction per child), St. Gallen and Thurgau (minimum amounts), Lucerne (state, municipal and church tax together at most 22.8 % or 22.4 % of taxable income), special assessment basis for church tax in Uri, Jura, Valais and Basel-Landschaft.
5. Net wealth minus tax-free allowance (by marital status and number of children; decreasing in steps in Fribourg), rounded down to CHF 1’000 → wealth tax tariff → simple wealth tax × tax multipliers; Geneva additionally with the cantonal supplementary tax; Basel-Stadt with a reduction for modest incomes.
6. Personal tax per municipality (doubled for married persons in Zurich, Solothurn and Ticino), in Geneva, Neuchâtel, Solothurn and Uri with the church poll tax per denomination.
7. Direct federal tax according to the tariff, less a fixed amount per child (parental tariff, 2025 and 2026: CHF 263); tax amounts below CHF 25 are not levied.

Measured accuracy

The tool is automatically checked against the FTA tax calculator. The check covers 1’888 cases in 142 municipalities across all cantons with random combinations of household, children, income (CHF 24’000 to 1.4 million), wealth (0 to 6 million), denomination and age, each with and without standard deductions, as well as targeted cases for every cantonal special rule (wealth-dependent deductions, tax burden caps, poll taxes, incomes up to 3 million). As of 14 October 2026:

• Total tax: in 99.6 % of cases a deviation of at most CHF 5, in 99.9 % at most CHF 15; largest deviation CHF 26.
• Taxable income (with standard deductions): largest deviation CHF 85, mean deviation CHF 0.5.
• Simple tax (tariff): largest deviation CHF 11.

Deviations arise from the interpolation of the deduction tables between reference points and from rounding. Every deviation discovered during operation is added as a test case.

Validity and updates

Every figure in the tool is tied to a tax year and is shown with its source and retrieval date (see the footer and the info icon next to the tax year). Tax year 2026 applies to income and wealth of the year 2026; the corresponding tax bill follows the next year. Available tax years: 2025, 2026.

• Cantonal tariffs are laid down by law and change only through legislative revisions or the annual adjustment for inflation; both are usually known a year in advance.
• Cantonal and municipal tax multipliers are set with the budget in the autumn of the preceding year (by municipal assemblies and parliaments, usually in November or December). Until then, they are not known for the following year.
• The FTA includes the new tax year as soon as the cantons have reported their data – usually in the first quarter. An automatic monthly check detects whether a newer complete tax year is available; it is then added here as an additional tax year that can be selected separately.
• Only the next tax year can be shown in advance, and only once the FTA includes it for all cantons. For a later move, the following applies: the differences between municipalities are far larger and more stable than the annual changes in tax multipliers, which usually amount to a few percentage points. The ranking from the current tax year is therefore a sound basis for the decision.

Calculated without AI, resource-efficient

The calculation does not use artificial intelligence. It runs deterministically and transparently in your browser using data tables provided in advance (a few hundred kilobytes) – no server request for the calculation, no account, no waiting. A complete calculation for all municipalities needs only a fraction of the energy of a single text prompt to an AI assistant (according to Google, a median of 0.24 Wh) and delivers figures that have been checked against the FTA tax calculator.

Open data

All tables the tool uses for its calculations are available in machine-readable form and may be reused with attribution (FTA tax calculator, prepared by steuerlandschaft.ch) – including by search engines and AI systems. For each tax year, at /data/‹year›/:

• municipalities.json – tax multipliers of all municipalities (income, wealth, church by denomination), personal taxes, FSO numbers.
• tariffs.json – tariffs of the cantons (single persons, married persons, child models) and of the federal tax, as reference-point tables.
• deductions.json – taxable income by gross income, household and number of children per canton; deduction-lines.json – the individual deduction items.
• wealth.json – wealth tax tariffs and tax-free allowances per canton.
• The ranking can be downloaded from the tool as CSV; a machine-readable overview is available at /llms.txt.

What is not covered

• Individual deductions (actual health insurance premiums, pillar 3a, debt interest, travel costs, further education, real estate, maintenance payments).
• Income types other than salary from employment: pensions, income from self-employment and investment income are treated as part of income, without their special rules.
• For married couples, a split of income other than equal halves and different ages of the spouses; children younger or older than 8; more than three children.
• Tax at source: foreign employees who live in Switzerland and do not hold a settlement permit (permit C) as a rule pay tax at source on their salary according to a tariff that is uniform throughout the canton; the ordinary taxes shown in the ranking apply to them only once a subsequent ordinary assessment is made (see FAQ). Lump-sum taxation, inheritance, gift and real estate capital gains taxes are likewise not covered.
• Special tax rules in the year of moving in or moving out.

Verification

Every calculation can be verified in the FTA tax calculator. Enter tax year 2026, home municipality, marital status, age, children (aged 8), denomination and gross income (half each for two incomes) there. The detail panel shows all inputs and intermediate values for this purpose.