Method and assumptions
Every figure on this site rests on assumptions. They are all listed here — with their vintage and their source, including where they are imprecise. This page is generated from the same registry the calculators read their values from (lib/assumptions.ts), so it cannot go stale without the calculation going stale with it.
Whose taxes are calculated
- The reference household
- Every pre-computed figure — reference taxes, ranking tables, comparison verdicts, municipality snippets — is for a single person, 35 years old, no children, no confession, no wealth, in employment. That is one case, not the case. In the calculators you set the profile yourself.
- As of: 2026Reference: lib/data/referenceTaxes.ts
- The reference incomes
- Figures are pre-computed at gross annual salaries of 60'000 · 80'000 · 100'000 · 120'000.
- As of: 2026Reference: lib/data/referenceTaxes.ts
- Age of children
- The form asks for the number of children, not their age. Ten cantons stage the child deduction by age, so the calculation uses a child of 8, which falls into exactly one band in each of those cantons. For markedly younger or older children the deduction differs by canton.
- As of: 2026Reference: WELLE1C-ABSCHLUSSBERICHT.md §4.2
Taxes
- Tax year and data source
- Tax year 2026. Rates, multipliers and deductions come from the cantonal data of the Federal Tax Administration; the engine is also checked against its calculator.
- As of: 2026Source
- BVG deduction
- The employee BVG contribution is deducted from gross salary: 5 % of the coordinated salary up to CHF 90'720, 3.5 % above, coordination deduction CHF 26'460. This is the flat rate the FTA calculator uses as well — your actual pension fund may differ.
- As of: 2026SourceReference: AUDIT-2026-09.md §3.1
- Social insurance
- AHV/IV/EO 5.3 %, ALV 1.1 %, NBU 0.4 % of gross salary. ALV and NBU only up to an annual salary of CHF 148'200.
- As of: 2026
- Checked against the FTA calculator
- Checked against the FTA detail calculator: 198/208 cases without children and 121/156 cases with children fall within ±3 %, across all 26 cantons and incomes from 60,000 to 200,000.
- As of: 2026Reference: WELLE1B §3, WELLE1C §3
- Where the numbers are not right yet
- Still open: in SZ, NW the tariff steps do not come from the official table. In AG, BE, FR, NE, SH an income-staged relief is missing that mainly affects low-income families. In those cantons the site tends to calculate too high; the affected pages say so.
- As of: 2026Reference: WELLE1C-ABSCHLUSSBERICHT.md §5
Rent
- Rents
- Rent for a 3-room flat, cantonal figure from the Federal Statistical Office, 2020. This value is identical for every municipality of a canton — these are not municipal rents, and they are not current.
- As of: 2020SourceReference: scripts/compute-rent-benchmarks.mjs:37
Health insurance
- Health insurance premiums
- Cantonal median for premium region 1, adults, basic insurance with accident cover, franchise CHF 2'500, FOPH data 2026. This value too is identical for every municipality of a canton.
- As of: 2026SourceReference: scripts/compute-insurance-premiums.mjs:83-91
- Premium deduction in the tax calculation
- The tax deduction for insurance premiums assumes CHF 4'560 per adult and CHF 1'200 per child, capped on the sum rather than per item — the way the FTA calculator does it.
- As of: 2026Reference: WELLE1C-ABSCHLUSSBERICHT.md §4.5
Salaries
- Salary data
- Salaries in the salary comparison: Swiss Earnings Structure Survey of the Federal Statistical Office, 2024.
- As of: 2024Source
How the numbers are formed
- Canton-level figures
- A cantonal figure is the unweighted mean of its municipalities: the smallest municipality counts as much as the largest city. A population-weighted mean would be the better number, but the population figures are not in the data set.
- As of: 2026Reference: WELLE2-ABSCHLUSSBERICHT.md §5.5
- Values in between
- Between the reference incomes the reading is linear. Measured against the engine the error is at most CHF 255; a break-even income derived from it, at most CHF 2'000.
- As of: 2026Reference: WELLE2-ABSCHLUSSBERICHT.md §5.4
- How ranks are assigned
- The rank in the ranking table is position-based: municipalities with the same tax multiplier get consecutive ranks, not a shared one. 1,839 of the 2,110 municipalities share their multiplier with at least one other — with shared ranks the municipality page would show a different number than the cantonal table.
- As of: 2026Reference: WELLE2-ABSCHLUSSBERICHT.md §3.4
No warranty is given. This page is not tax advice; only the assessment issued by your tax authority is binding.