CalculatorBin

Editorial Policy

CalculatorBin publishes free calculators and guides that people use to make real decisions — buying materials, planning a budget, cooking a turkey safely. This policy explains how we make sure those numbers can be trusted.

Who is responsible

Every calculator and guide is built and reviewed by Anirban Kundu, Creator & Editor (M.Sc in Physics, B.Ed, M.A in Education; 20 years teaching science and physics). His name and the last-reviewed date appear on each calculator page.

Sources we rely on

  • Government and official bodies: IRS, U.S. Department of Labor, USDA Food Safety and Inspection Service, U.S. Energy Information Administration, U.S. Department of Energy, NREL, Consumer Financial Protection Bureau, U.S. Office of Personnel Management.
  • Manufacturers’ technical data sheets for product yields and coverage (for example concrete, grout, thin-set and underlayment).
  • Building code references for stairs, footings and similar limits, and university extension services for lawn and garden rates.
  • Standard mathematics and physics for formulas.

We do not cite anonymous forums or other calculator sites as a source for a number. Each page lists the sources it uses.

How a calculator is built and checked

  1. The formula and its assumptions are written down and at least one case is worked by hand.
  2. The calculator is coded so the worked example and any reference tables on the page are generated by the calculator itself — they cannot drift from the tool.
  3. Automated tests compare results with hand-checked answers and try extreme values, every option and blank inputs.
  4. Results that you buy in whole units (bags, boxes, sheets) are rounded up, and the waste allowance is always shown and editable.

Money, tax and safety topics

Financial calculators are planning tools, not advice. They show every assumption — rates, limits, fees — and let you change them. Yearly figures such as contribution limits or tax rates are dated on the page and reviewed when official values change. Food-safety and building pages follow the official guidance they cite and tell you when a professional or inspector should make the call. We do not publish medical dosing calculators.

Updates and corrections

Each calculator shows a “Last reviewed” date. When a source changes — a new tax year, a new code edition, a new data sheet — we update the calculator and the date. If you find an error, email calculatorbin@gmail.com with the page and the numbers you entered. Confirmed errors are corrected promptly.

Independence

No company pays to appear in our calculators or to change their results. If we ever show advertising, it will be clearly separated from the calculators and will never affect their numbers.