Methodology
SalaryExit uses a single TypeScript calculation layer with automated tests. This page explains what is exact arithmetic, what is modeled, and what is out of scope — not legal or tax filing advice.
Financial year and tax engine
Income tax slabs, standard deductions, and Section 156 rebates under the Income Tax Act, 2025 (earlier Section 87A framework), including new-regime marginal relief just above the rebate threshold) follow the configured financial year (Tax Year 2026–27 (FY 2026–27) tax slabs in engine). Values are defined in code and should be reviewed after each Union Budget. Surcharge (₹50L+ taxable) and its marginal relief are not modeled.
Policy sync for visitors: Calculator tax math was last aligned to Union Budget 2026 — no slab changes; Income Tax Act, 2025 Tax Year 2026–27; new regime (Section 202, earlier 115BAC) slabs from Budget 2025 continue; Section 156 rebate (earlier 87A) ≤₹12L taxable; std. deduction ₹75,000 (Section 19(1)); cess 4%. New-regime rebate / marginal relief is modeled; surcharge is not — validate Form 16 and CBDT circulars for filing. Editorial methodology copy last reviewed: July 2026. Separately, the employee PF wage-ceiling model was revised on 14 October 2026 for the 17 September 2026 statutory ceiling (documented PF release notes) — that date is a model update, not a claim that every page of site prose was re-reviewed then.
What is "exact" in math terms
Given the same inputs and assumptions, the engine applies the same formulas every time: slab tax, cess on tax after rebate, PF on wage (with optional ceiling), and simple aggregations (e.g. final settlement sums).
What is estimated or simplified
- TDS smoothing — annual tax is often spread ÷ 12 for monthly in-hand; real payslips vary by month.
- Section 156 rebate (earlier Section 87A) — implemented as a simplified model; verify against the Income Tax Act, 2025 / Finance Act for your tax year.
- Bonus, arrears, perquisites, stock — not modeled unless you fold them into gross consistently.
- PF — employee contribution is rate × PF wage (with optional statutory ceiling). Current monthly examples use the ₹25,000 ceiling effective 17 September 2026; Tax Year / FY 2026–27 totals for existing capped members use the documented mid-year transition. Employer EPS/EDLI splits are not shown.
- Professional tax — you supply a placeholder or realistic annual amount; we do not ship state-wise tables.
- Gratuity / leave tax — statutory formulas and rough exempt bands; final tax treatment is fact-specific.
CTC → in-hand flow (summary)
- Derive employee PF annual from explicit PF or from Basic+DA via configured PF rules.
- Compute income tax + cess for the chosen regime on gross (with standard deduction and limited deductions per tool).
- Subtract PF, professional tax, and monthly TDS spread from monthly gross to get in-hand.
Where to read formula details
Contributors can find deeper formula notes and a calculator-by-calculator audit (exact vs estimated) in the project repository alongside the code. On this site, the sections above summarize what visitors should rely on.
Updates
Two dates matter, and they are not the same: content / methodology copy was last reviewed in July 2026; the PF calculation model was last revised on 14 October 2026 for the 17 September 2026 wage-ceiling change. Engine FY label: Tax Year 2026–27 (FY 2026–27) tax slabs in engine. We do not backdate a full editorial review to the PF model revision date.
Page content last reviewed: July 2026. For calculation scope and FY assumptions, see methodology.