Methodology

Simple enough to use. Clear enough to check.

Our calculators are educational planning models. They prioritize transparent assumptions and useful comparisons over false precision. Each result page states what the model includes and where a real paycheck, loan, or savings account can differ.

Calculation standards

• Pay tools: show gross amounts unless a field explicitly asks for a deduction estimate.
• W-2 vs. 1099: uses the standard 7.65% employee Social Security and Medicare rate and estimates self-employment tax at 15.3% of 92.35% of net business earnings. It intentionally excludes income tax.
• Commute comparison: subtracts entered fuel and recurring travel costs, and displays commute time separately. It does not assume a universal mileage cost.
• PTO value: divides annual salary across 260 weekdays, then values paid days while keeping that value inside—not on top of—salary.
• Bonus estimate: defaults to the 2026 optional 22% federal withholding rate for separately identified supplemental wages up to $1 million. Withholding is not final tax.
• Debt tools: approximate monthly interest using APR divided by 12, apply payments monthly, and assume fixed rates with no fees or new charges.
• Savings tools: approximate monthly compounding from APY and assume deposits and rates remain constant. The sinking-fund tool intentionally excludes interest.
• Dates: begin in the current month and are estimates, not contractual payoff or maturity dates.

Primary references

We favor official sources for the rules and terminology that influence our explanations.

• U.S. Department of Labor — Overtime Pay
• IRS Publication 15 (2026) — Employer’s Tax Guide
• IRS Topic No. 751 — Social Security and Medicare Withholding Rates
• IRS Topic No. 554 — Self-Employment Tax
• Consumer Financial Protection Bureau — Emergency Fund Guide
• FDIC — Deposit Insurance

Review and corrections

Pages show their most recent review date. We review formulas, defaults, examples, and explanatory copy together because a technically correct formula can still mislead when an assumption is hidden. We also test zero values, high interest rates, and unreachable payoff scenarios. Read the full Editorial Policy for sourcing and AI-assistance disclosures.

Important: Results are estimates and do not replace a pay statement, contract, account disclosure, professional advice, or a lender’s official payoff quote.