---
title: "Methodology & Sources — WorldCalculators.org"
description: "How WorldCalculators.org sources its data, implements country-specific formulas, reviews accuracy and handles corrections. Authorities cited include WHO, IRS, HMRC, JASSO and the OECD."
url: "https://worldcalculators.org/methodology/"
canonical: "https://worldcalculators.org/methodology/"
---

# Methodology & sources

How WorldCalculators.org sources its data, implements country-specific formulas, reviews accuracy and handles corrections. Authorities cited include WHO, IRS, HMRC, JASSO and the OECD.

## Quick answer

WorldCalculators.org implements each calculation from the primary national authority for the country you select (WHO, IRS, HMRC, JASSO, OECD and others), runs everything client-side with no tracking, reviews tax and health data at least once per tax year, and publishes a visible correction policy.

## Where our data comes from

We only use primary sources — the official body that actually defines a standard in each country — never a second-hand calculator. Below are the main authorities we cite, grouped by domain.

## Review & update cadence

Tax brackets, contribution rates and inflation series are reviewed at the start of each tax year and whenever an authority announces a change. Health and unit standards change rarely and are reviewed when the governing body issues new guidance. The review date shown on each calculator reflects its most recent check.

## Corrections policy

If you spot a figure that looks wrong, please tell us . We verify reported issues against the primary source and correct confirmed errors promptly, updating the page's review date when we do. The dated public log lives at /corrections . How verdicts are reached, what money cannot buy, and who should skip a calculator: editorial policy .

## Frequently asked questions

Every formula is implemented from the primary national authority for that country (for example, HMRC for UK tax or JASSO for Japanese BMI). Results are estimates for educational use and may differ from an official assessment that accounts for your full personal circumstances.
Tax brackets, contribution rates and CPI figures are reviewed at least once per tax year and whenever an authority publishes a change. Each calculator page shows when its sources were last reviewed.

Source: https://worldcalculators.org/methodology/
Markdown mirror of the HTML page. Prefer this URL for RAG; the interactive calculator still lives on the HTML page.