Methodology

This page describes how Calculatories sources, verifies, and maintains the data behind our calculators. Transparency about our methods is essential for YMYL (Your Money or Your Life) content.

Formulas & Calculations

All calculator logic uses standard, widely accepted formulas. For example, our mortgage calculator implements the standard amortization formula used by lenders nationwide. Formula implementations are reviewed by subject-matter experts and tested against known benchmarks before publication.

Default Values & Rates

Default interest rates and financial figures reflect recent national averages published by the Federal Reserve (H.15 release) and Freddie Mac Primary Mortgage Market Survey. We update defaults when published averages shift by more than 0.25 percentage points.

Localized & Programmatic Data

Location-specific pages (e.g., state mortgage calculators) pull median home prices and tax rates from the US Census Bureau American Community Survey (ACS). Each localized figure includes the data vintage (year) and a direct link to the source. We do not publish location pages without genuinely differentiated local data.

Health Metrics

Health calculators align with guidelines from the CDC, NIH, and WHO where applicable. BMI categories follow WHO standards. Calorie and nutrition tools use Mifflin-St Jeor or Harris-Benedict equations as appropriate, reviewed by our registered dietitian.

Update Schedule

• Mortgage rate defaults: reviewed monthly
• Census/localized housing data: reviewed annually
• Tax brackets and thresholds: reviewed when IRS publishes updates
• Health guidelines: reviewed when CDC/NIH issues revisions
• All YMYL page content: full review at least annually

Read our editorial policy for information on authorship and review processes.