These tools make financial calculations using the inputs and assumptions shown on each page. This page explains how the models are maintained and how to interpret their results.
How calculations are checked
Pure calculation functions are checked against independent equations, selected published examples and official parameter tables. Loan schedules are checked for principal conservation and final-payment limits. Worked examples link to reproducible calculator inputs.
Review status
Automated mathematical checks and selected reference cases are available in the public project. Complete equivalence with every original Calculator.net option, submission and visual detail remains under review. A passing default-input test is evidence of local operation, not proof of every business rule.
Data versions and scope
- Federal tax estimates offer selected 2025 and 2026 rules; state/local tax, eligibility and complete return preparation are outside the stated model.
- 401(k) and IRA projections keep the published 2026 contribution limits constant in future years; full plan eligibility and aggregate limit rules are not inferred.
- Owner-account RMD tables use IRS distribution factors effective from 2022. Inherited accounts and some plan exceptions require separate treatment.
- Historical inflation uses BLS CPI-U records; missing official periods are not interpolated. Future inflation is an entered assumption.
- Currency conversion uses your manually entered rate or a bundled dated historical snapshot. No external API is contacted; saved rates are not live market quotes.
Timing and rounding
Payment, contribution and withdrawal timing is model-specific. Calculations retain floating-point precision and display monetary amounts to two decimals. Lender daily-interest calculations, invoice-level tax rounding and independently rounded totals can differ from a planning model.
Sources and changes
Official source links appear with relevant calculation guides and result notes. The public source repository contains calculation code, tests and research. Read the calculation audit for identified fixes and remaining gaps.
Using the results
Check the units, tax year, jurisdiction and assumptions before comparing scenarios. Forecast returns are assumptions. Verify contractual payments, tax filings and benefit eligibility with the relevant lender, authority or qualified adviser.