Instant accuracy
Every tool calculates in real-time. No submit buttons, no waiting — just answers as you type.
About Calcrux
Built for the businesses that keep the world running
Calcrux is a free calculator and simulator platform for the people who actually run businesses — sellers, manufacturers, founders, and finance pros.
Our mission
Too many business decisions are made on gut feeling because the right tool is behind a paywall, buried in a spreadsheet, or simply doesn't exist. We're building 500+ precision tools — calculators, simulators, estimators — that anyone on the planet can use, free, forever.
What we stand for
Three principles, no compromises
Global first
Auto-detects your country. Adapts currencies, tax labels, and number formats for 150+ countries.
Privacy by design
All calculations happen in your browser. Your numbers never touch our servers.
How we build
Engineering principles
01
Real business logic
Engines model how Amazon FBA fees, OEE, runway, or SIP returns actually work — not a generic formula.
02
Tested calculations
Every tool ships with unit tests covering edge cases. We treat correctness as a feature.
03
Free forever
No premium tier, no credits, no signup. Free tools should stay free.
04
Open by default
Formulas are explained in every FAQ. No black boxes — you can verify every result.
Where we're going
500+ tools across 5 ecosystems
We're launching 500+ tools across five ecosystems: Ecommerce, India Business, Manufacturing, Startup & BI, and Operational Financial Planning. Each tool is built with real business logic, tested against actual use cases, and kept current with platform fee changes.
Every tool is free. No premium tier, no credits, no account required — ever.