Methodology
Data Sources
CalcPeek calculators and unit converters are built on internationally recognized measurement standards. Our conversion factors come from the following authoritative sources:
- International System of Units (SI) — The global standard for measurement, maintained by the International Bureau of Weights and Measures (BIPM).
- National Institute of Standards and Technology (NIST) — U.S. federal agency providing precise conversion factors and measurement standards.
- IEEE Standards — For digital storage and computing-related conversions (binary vs. decimal prefixes).
Conversion Accuracy
All unit conversions use exact mathematical formulas with full floating-point precision. Linear conversions (length, weight, volume, area, speed, pressure, energy) multiply by scientifically established factors. Non-linear conversions (temperature) use the correct formulas — for example, Celsius to Fahrenheit uses °F = °C × 9/5 + 32, not a simple multiplier.
Results are displayed with appropriate decimal precision based on the magnitude of the value. Very small or very large values use scientific notation when necessary.
Calculator Formulas
Our calculators use well-established formulas from their respective fields:
- BMI Calculator —
BMI = weight (kg) / height (m)², with WHO classification thresholds. - Mortgage Calculator — Standard amortization formula:
M = P × [r(1+r)^n] / [(1+r)^n – 1]. - Loan Payoff Calculator — Iterative amortization schedule with monthly compounding.
- Investment Calculator — Compound interest:
A = P(1 + r/n)^(nt)with optional regular contributions. - Tip Calculator — Simple percentage:
tip = bill × tipRate, with per-person split. - Age Calculator — Exact date arithmetic accounting for leap years and varying month lengths.
Digital Storage Conversions
We use the binary standard (IEC 80000-13) for digital storage conversions. This means 1 kilobyte = 1,024 bytes, 1 megabyte = 1,024 kilobytes, and so on. This is the convention used by operating systems and most software. We clearly label all units to avoid confusion between binary (KiB, MiB) and decimal (kB, MB) interpretations.
Quality Assurance
Every conversion factor and calculator formula is cross-referenced against at least two independent sources. We regularly audit our conversion tables against NIST published values. If you find any discrepancy, please contact us — accuracy is our top priority.
Limitations
Our calculators provide estimates for educational and planning purposes. Financial calculators (mortgage, investment, loan) do not account for taxes, fees, insurance, or other costs that may apply in real-world scenarios. Always consult a qualified professional for important financial decisions.
BMI calculations provide a general health indicator but do not account for muscle mass, bone density, age, or ethnic background. Consult a healthcare professional for personalized health assessments.