I’m Fil J., a finance professional with over six years of hands-on experience across financial market supervision, corporate finance and portfolio management — on top of five years of formal finance education.
I’ve spent my career working at the intersection of markets, regulation and investment analysis. That means I’ve evaluated financial instruments from multiple angles — not just as an investor trying to maximise returns, but as someone responsible for understanding how they behave under stress, how they’re priced in practice, and where standard models break down in the real world.
That background is what shapes how FinanceFriend24 is built. Every calculator on this site is designed to match how these instruments actually work in professional practice — not simplified versions that give you a rough idea. Every guide is written to explain not just the definition, but the mechanics behind it, the assumptions baked in, and the situations where the standard formula stops being reliable.
During my years working in financial markets, I kept running into the same frustration: the tools that professionals actually use were either locked behind expensive Bloomberg terminals, buried in academic papers, or simply didn’t exist in an accessible form online.
If you wanted to calculate a bond’s effective duration accounting for embedded options — you needed specialist software. If you wanted to understand how repo haircuts affect balance sheet capacity — you’d find a few textbook definitions and not much else. If you needed to calculate the Sortino Ratio properly, accounting for lower partial moments rather than just total volatility — good luck finding a free tool that did it right.
FinanceFriend24 was built to close that gap. Whether you’re a finance student trying to understand how bond duration actually works, a retail investor evaluating a fixed income portfolio, or a professional who needs a quick calculation without opening a spreadsheet — this site is for you.
Free professional-grade calculators covering bonds, mortgages, investment performance metrics, and more — built to the same standards used in professional practice, not dumbed-down approximations.
In-depth guides on financial instruments, investment analysis and personal finance — written to explain the mechanics behind each concept, not just the surface-level definition.
Honest explanations of limitations — every metric has assumptions and edge cases where it breaks down. You'll find those explained here, because understanding when not to use a tool is as important as knowing how to use it.
All content is free. No paywalls or no signup required
FinanceFriend24 is designed for a global audience. While I’m based in Europe, the calculators and guides are built around internationally used financial concepts and instruments — US Treasuries, corporate bonds, standard mortgage structures, and performance metrics used across global markets.
Where concepts vary meaningfully by jurisdiction (tax treatment of bonds, specific mortgage regulations), I try to flag that clearly rather than presenting one market’s conventions as universal.
If you spot an error in any of the content, have a suggestion for a new calculator, or want to request coverage of a specific topic — I read every message. Use the contact page to reach me directly.
FinanceFriend24 is a constantly growing project. New calculators and guides are added regularly based on what’s most useful to readers.
— Fil J., Founder of FinanceFriend24