Methodology
Methodology
This page explains how Free Calculation Tools selects formulas, tests calculators, updates assumptions, and communicates limitations. Our goal is to make every calculator understandable before it is relied on.
1. Formula selection
We use standard formulas commonly taught in math, finance, and science education, or formulas widely used by lenders, publishers, and reference institutions for the topic involved. For health and finance tools, we prefer established reference methods over custom scoring systems.
2. Calculator checks
- We test normal inputs and obvious edge cases.
- We compare outputs against hand calculations, spreadsheet checks, or trusted reference examples where possible.
- We review rounding behavior, units, and explanatory labels before publishing.
3. Sensitive-topic tools
Mortgage, insurance, debt, calorie, BMI, pregnancy, and similar calculators are educational planning tools only. They simplify real-world decisions and cannot account for every personal, legal, medical, or market-specific variable.
4. Sources and assumptions
Whenever a calculator depends on assumptions rather than a single universal formula, we try to state those assumptions on the page itself. Examples include expected investment return rates, insurance premium ranges, calorie activity multipliers, or advertising revenue estimates.
5. Updates
Pages are updated when formulas change, when assumptions need clarification, when wording creates confusion, or when readers report an issue. Substantial page changes should be reflected in the updated date shown on the page.
6. Limitations
No calculator on this site should be treated as a substitute for licensed medical, legal, tax, or financial advice. Use our tools to estimate, compare scenarios, and understand the math – then confirm high-stakes decisions with a qualified professional.