Our Mission
ProCalcTools was created to solve a simple problem: most calculator websites are cluttered with intrusive ads, outdated formulas, or results that are difficult to trust. We set out to build a small, focused library of calculators — covering mortgages, loans, BMI, calories, grades, paychecks, and more — that are fast, mobile-friendly, and based on formulas you can verify yourself.
Every tool on this site runs entirely in your browser. We don't require sign-ups, we don't store the numbers you enter, and we don't sell your data — because we don't collect it in the first place.
How We Build Our Calculators
Each calculator on ProCalcTools is built around a publicly documented formula or government/industry standard. For example:
- Our mortgage and loan calculators use the standard amortization formula used by lenders to compute principal and interest.
- Our calorie calculator uses the Mifflin-St Jeor equation, recommended by the Academy of Nutrition and Dietetics as the most accurate BMR formula for the general population.
- Our BMI calculator follows the CDC's standard BMI formula and adult weight-status categories.
- Our grade calculator uses standard weighted-average math that matches how most US schools compute final grades.
Before publishing a new calculator, we manually test it against known examples and, where possible, cross-check results against official calculators (such as those published by the CFPB, CDC, or IRS) to confirm accuracy.
Our Editorial Process
Alongside our calculators, we publish guides and articles that explain the math behind the numbers — things like how mortgage rates work, what a healthy BMI range looks like by age, or how to calculate a weighted grade. These articles are:
- Written in plain language, avoiding unnecessary jargon.
- Based on current data for the year referenced in the title, and updated as rates, rules, or guidelines change.
- Reviewed for accuracy before publishing, with formulas double-checked against the calculator output they describe.
We link to original sources — such as government agencies, financial regulators, and recognized health organizations — wherever a claim depends on official data.
What ProCalcTools Is Not
ProCalcTools is an educational and informational resource. It is not a substitute for advice from a licensed financial advisor, accountant, physician, or other qualified professional. Our calculators provide estimates based on the inputs you provide and standard formulas — actual results from lenders, employers, schools, or healthcare providers may differ. Always confirm important financial or health decisions with a qualified professional.
Questions or Corrections?
If you notice an error in a calculation, have a suggestion for a new tool, or want to report an issue with an article, please visit our Contact page. We review all messages and aim to respond within 1–2 business days.
You can also read our Privacy Policy and Terms of Use for more details on how this site operates.