Clearer numbers, calmer decisions.
CortexCalculator started with a simple frustration: every good financial calculator was either behind a paywall, buried in ads, or asking for an email. So we built the opposite.
Financial clarity, free for everyone.
We believe everyone deserves access to the same financial math that lenders, advisors, and accountants use — without the friction, the upsell, or the privacy trade-off.
That's why every CortexCalculator tool is free, private, and instant. Always has been. Always will be.
Four principles guide every tool we build.
Privacy first
Every calculation runs in your browser. We never see your numbers and we never want to.
Instant by default
No accounts. No loading screens. Open a tool and get an answer in under a second.
Honest math
We publish the formulas we use, refresh tax tables yearly, and show our work.
AI where it helps
We use AI to explain results in plain English — never to manufacture financial advice.
Pick a number. We'll do the math.
Browse the full library — no signup, no friction.
Browse calculators