Methodology · Versioning
Our calculations evolve. Here's how we track it.
Every calculator on SalaryLabs has a version number, a changelog, and documented assumptions. We use semantic versioning — MAJOR for formula change, MINOR for new input, PATCH for bug fix. This page is the master record of what we compute, what changed, and when.
Versioning policy
MAJOR
Formula change
Output for the same input may differ from the previous version. Examples: new federal tax brackets, new SSA wage base, new FLSA threshold.
MINOR
New input
Existing input/output pairs produce identical results. New input field added. Examples: HSA contribution field, state picker for new state.
PATCH
Bug fix / display
No calculation change. Examples: copy fix, alignment, edge-case rounding, missing label.
Current versions (all 16 calculators)
The most recent version of every calculator. Each row links to the live tool; the changelog below shows what changed.
| Calculator | Version | Last updated | Most recent change |
|---|---|---|---|
| Take-Home Pay | v2.4.0 | 2026-01-15 | OBBBA 2026 federal brackets + standard deduction |
| Salary Calculator | v1.2.0 | 2025-12-01 | Hourly basis updated to 2,080 hours/year (industry standard) |
| Salary to Hourly | v1.2.0 | 2025-12-01 | Hourly basis updated to 2,080 hours/year |
| Hourly to Salary | v1.2.0 | 2025-12-01 | Hourly basis updated to 2,080 hours/year |
| Income Breakdown | v2.3.0 | 2026-01-15 | OBBBA 2026 federal brackets + Medicare surtax thresholds |
| Income Percentile | v1.4.0 | 2025-11-10 | Refreshed to BLS 2024 OEWS data (annual update) |
| Tax Estimator | v2.4.0 | 2026-01-15 | OBBBA 2026 brackets and capital gains rates |
| Overtime Calculator | v1.8.0 | 2025-07-01 | FLSA salary threshold update ($684/wk → $844/wk, $43,888/yr → $58,656/yr) |
| Retirement Stack | v2.1.0 | 2026-01-15 | OBBBA 2026 contribution limits (401k $23,500; IRA $7,000; HSA $4,300 single / $8,550 family) |
| Backdoor Roth | v1.5.0 | 2025-12-01 | IRS Form 8606 step-by-step formula updates |
| Salary Comparison | v1.1.0 | 2025-09-01 | Side-by-side annual / monthly / weekly display added |
| Job Offer Comparison | v1.3.0 | 2025-10-15 | Signing bonus proration + 4-year equity vesting scenarios |
| Salary Time Machine | v1.2.0 | 2025-11-10 | CPI-U series through October 2025 |
| US Salary Heatmap | v1.4.0 | 2025-11-10 | BLS OEWS state-level data refresh |
| Burnout Calculator | v1.0.0 | 2025-06-01 | Initial release (heuristic model, not a clinical tool) |
| Negotiation Script | v1.6.0 | 2026-01-15 | BLS wage data refreshed + prompt template updated for OBBBA 2026 |
Recent changelog
Newest first. Click a calculator name to open the live tool with the current version. Past versions are not exposed in the UI but can be reproduced from this changelog.
v2.4.02026-01-15
Affected:take-home-pay, income-breakdown, tax-estimator, retirement-stack, negotiation-script
- Updated federal income tax brackets to OBBBA 2026 schedule (Rev. Proc. 2025-32)
- Updated standard deduction: $15,750 single / $31,500 married (up from $15,000 / $30,000)
- Updated 401(k) elective deferral limit: $23,500 (up from $23,000)
- Updated HSA contribution limit: $4,300 single / $8,550 family (up from $4,150 / $8,300)
- Updated catch-up contribution limits for 50+
- Negotiation script prompt updated to use OBBBA 2026 wage anchors
v1.8.02025-07-01
Affected:overtime-calculator
- FLSA salary threshold updated: $684/week → $844/week (effective July 1, 2024 DOL rule, applied retroactively to calculator results)
- Annualized threshold: $43,888/year → $58,656/year
- Highly compensated employee threshold: $132,864/year → $151,164/year
- Note: DOL published a 2025 rule to raise the threshold further; we will apply that when the rule is finalized.
v1.6.02026-01-15
Affected:negotiation-script
- AI prompt updated to include OBBBA 2026 federal brackets as wage anchor
- Added OBBBA-specific tips for senior taxpayers (additional standard deduction, etc.)
v1.5.02025-12-01
Affected:backdoor-roth
- IRS Form 8606 step-by-step formula updates
- Added non-deductible basis tracking explanation
- Clarified pro-rata rule calculation for multiple IRA balances
v1.4.02025-11-10
Affected:income-percentile, salary-time-machine, salary-heatmap
- BLS OEWS May 2024 release data refresh (annual update)
- Updated CPI-U series through October 2025
- Refreshed state-level wage data for the heatmap
v1.3.02025-10-15
Affected:job-offer-comparison
- Signing bonus proration logic (one-time vs first-year-only)
- 4-year equity vesting scenarios with cliff and refresh dates
- Clearer display of health-insurance employer contribution
v1.2.02025-12-01
Affected:salary-calculator, salary-to-hourly, hourly-to-salary
- Hourly basis updated to 2,080 hours/year (industry standard: 40 hrs/week × 52 weeks)
- Documentation updated to clarify that 2,080 does not include paid time off
v1.1.02025-09-01
Affected:salary-comparison
- Side-by-side annual / monthly / weekly display added
- Per-hour equivalent for non-salaried comparisons
What triggers a version bump
The full list of events that change calculator behavior. Calendar events are predictable; regulatory events may be quick.
| Event | Example | Bump type |
|---|---|---|
| New tax year | Each January 1, federal tax brackets and standard deduction update | MAJOR |
| New FLSA rule from DOL | 2024-2025 DOL rule updates to the salary threshold for exempt status | MAJOR |
| New SSA wage base | October/November SSA notice effective the following January 1 | MAJOR |
| New IRS Rev. Proc. mid-year | OBBBA technical corrections or IRS-published clarifications | MAJOR or MINOR |
| BLS OEWS annual release | April/May wage data refresh | MINOR |
| New calculator input | Added HSA contribution as a new input field | MINOR |
| Bug fix in calculation | Off-by-one error in standard deduction for MFJ | PATCH |
| Copy edit or display change | Updated default state from "Generic 5%" to "TX no tax" | PATCH |
Documented assumptions
The defaults we use when you don't override them. Every calculator exposes the inputs needed to override these — the defaults are a shortcut, not a black box.
- We use current tax year federal brackets (IRS Pub. 15-T) and standard deduction by default. Users can override filing status and state tax rate.
- FICA math: 6.2% Social Security on wages up to the annual wage base, 1.45% Medicare on all wages, plus 0.9% Additional Medicare Tax on wages over $200,000 (single) / $250,000 (MFJ).
- State income tax is user-provided. We do not maintain a per-state tax calculator because state rules vary too widely (no-tax, flat, graduated, local add-ons). The default is a generic 5% which is the median state rate as of 2024.
- Pre-tax 401(k) contributions reduce federal taxable wages (subject to IRS limits), but do not reduce FICA wages. We model this correctly.
- We do not model state-specific credits (EITC state supplements, child tax credit state supplements, etc.) because the rules and amounts vary by state and filing status. Users with complex state situations should consult a tax professional.
- Pay periods are assumed to be 26 biweekly or 52 weekly by default. The take-home pay calculator outputs annual, monthly, and per-paycheck figures using the selected pay frequency.
- No imputed income, no RSU vesting tax modeling, no ESPP discount modeling. The retirement stack calculator handles 401(k) / HSA / IRA only.
- Wage percentile data (income percentile, salary heatmap) is from BLS OEWS, the most recent annual release. We do not interpolate or model missing data points.
Version in the API
The /api/v1/calculateendpoint returns the version in every response, so your integration always knows what formula it ran. Example response:
{
"tool": "take-home-pay",
"version": "2.4.0",
"input": { "salary": 85000, "filing_status": "single", "state": "TX" },
"result": { "net_annual": 71390, "net_monthly": 5949, "net_per_paycheck": 2745 },
"meta": {
"data_current_as_of": "2026-01-15",
"source_version_stamp": "irs-brackets-2026.0"
}
}Frequently asked questions
How do I know which version of a calculator I used?
Every calculation in the UI shows a version stamp at the bottom — typically formatted as "v2.4.0 · updated 2026-01-15". If you export a calculation as PDF, the version is embedded in the footer. The /api/v1/calculate endpoint also returns the version in the response JSON under the `version` key.
Can I get the old version's calculation if I need to compare?
Yes. If you ran a calculation in 2025 under the pre-OBBBA bracket math, your browser cached the inputs and the output, but the calculator no longer exposes the old formula. To reproduce, you'd need to look at our archive (links below in the changelog section). For audit-sensitive comparisons, we recommend saving the calculation PDF or screenshot with the version stamp visible.
How often do calculators change?
MAJOR bumps (formula change) happen on a calendar cycle: federal tax brackets every January 1, SSA wage base every January 1, FLSA thresholds when DOL publishes a final rule (typically every 2-4 years). MINOR bumps (new inputs) happen on demand — we ship when there's a reason. PATCH bumps (bug fixes) happen within days of a reported issue. We publish a new changelog entry for every bump.
Who decides when to bump a version?
A bump requires review by the founder (Wahyu Agustiar) and verification against primary sources (IRS, BLS, SSA, DOL). The review checklist is: (1) cite the primary source that changed, (2) update the formula, (3) regression-test against at least 10 known inputs, (4) update the changelog with a date. We do not ship silent changes.