How our calculators and data work

Rules every tool follows

• Facts, estimates and recommendations are labelled differently. Pay components carry a certainty label: guaranteed, target, expected, estimate or unknown.
• Unknown is not zero. Missing inputs are listed and excluded from totals.
• One-time and recurring amounts are kept apart, and first-year totals are shown separately from later years.
• Time is not money unless you choose a value for your time; even then it's reported separately from cash.
• Benchmarks are not predictions. Occupation wage data describes groups of workers, not you.
• No universal winner for job or career decisions.

Exact money maths

Calculations use exact decimal arithmetic (fractions, not floating-point numbers) and round only for display, to the cent, rounding halves away from zero. Every calculator has a versioned identifier shown with its result, so a change in method is visible.

Data sources and versions

• Federal tax: ruleset us-federal-2026 v1.0.0 (tax year 2026), from IRS Rev. Proc. 2025-32, IRS Publication 15-T (2026), IRS Topic 560 and the SSA 2026 COLA fact sheet. See the paycheck calculator sources.
• Wages by occupation: BLS Occupational Employment and Wage Statistics, May 2025 (released 2026-05-15). See the salary data methodology.
• Price levels by state: BEA Regional Price Parities, 2024 (updated February 19, 2026). See the cost of living sources.
• Other figures in guides (for example IRS mileage rates, Census commute times, KFF health premium surveys) are cited where they appear, with the date we accessed them.

Imported data files are recorded with their checksum, retrieval date and importer version; every displayed statistic is traceable to its source record.

Quality checks

Before any release, the site passes automated checks: unit tests for every calculation (including worked examples from official sources), integrity tests that re-derive published tax tables, build tests for links, titles and indexing rules, accessibility and layout tests in a real browser at phone, tablet and desktop sizes, and a type check and lint.

What we don't do

• We don't give financial, tax or legal advice.
• We don't model state or local income taxes yet.
• We don't publish pages just because a search term exists: data pages appear only when there's enough published data to be useful.