Calculate Anything.
Understand Everything.
CALTRX is a free calculator platform built around one principle: a number without an explanation is useless. Every result comes with the formula, the steps, and the context to help you actually understand what you calculated.
Step-by-Step Results
Every calculator shows the full calculation — not just the answer. You see each step, the formula used, and why it works.
Private by Design
All calculations run entirely in your browser. Nothing you type is sent to our servers. No account, no tracking of your inputs.
Always Free
Every tool on CALTRX is completely free. No premium tier, no paywalled features, no hidden limits. Just open and calculate.
What We Cover
365 calculators across 10 categories — from everyday math to professional-grade tools.
Our Approach to Accuracy
Every calculator on CALTRX is built from standard, peer-reviewed, or officially published formulas — including IRS tax tables, WHO BMI classifications, IOM dietary guidelines, and IEEE electrical standards.
If a formula has multiple recognized variants, we present all of them and explain the differences. You deserve to understand not just the result, but which method produced it and why.
Have a question or suggestion?
We read every message. Found an error, want a new calculator, or just want to say hello — reach out.