Methodology
How RetirementCalculator.dev separates formulas, assumptions, public rules, and user inputs.
RetirementCalculator.dev separates four things: user inputs, mathematical formulas, planning assumptions, and legal or program rules. Keeping them separate makes results easier to explain and future rule changes easier to maintain.
Key points
- User inputs are values you control or provide
- Mathematical formulas handle compounding, amortization, tax brackets, and similar relationships
- Planning assumptions include future return and inflation
- Rule packs contain country or program-specific facts from authoritative sources
How this fits into retirement planning
When a calculator cannot responsibly reproduce an individualized government benefit, it asks the user for an official estimate or limits the scope instead of manufacturing false precision.