Frequently asked questions
Answers to common questions about FinSimLab calculators, methodology, data sources and privacy.
What is FinSimLab?
FinSimLab is a free platform to learn personal finance and make better decisions with real numbers. It includes mortgage, loan, rental property, compound interest, stock fundamental analysis, stock comparison and crypto DCA calculators, plus an Academy with more than 90 guides. A personal finance dashboard is in development and will be part of the Pro plan.
Are the simulations accurate?
The simulators use standard financial formulas (standard amortisation, IRR, NPV, NOI, cap rate, P/E, ROE and P/B ratios), the same analysts use. Even so, results are estimates: fees, rate changes, inflation or market moves can change the outcome. For important decisions, always complement them with professional advice.
Do I need to create an account?
No. All calculators, the stock comparison tool, the Academy and PDF export work without an account and without sharing any personal data.
Is FinSimLab free?
Yes. The calculators, the Academy and PDF export are free and will stay free. We are building a Pro plan with the dashboard and the advanced stock features; while we finish it you can use those features for free. When it is ready we will publish here what it includes and what it costs.
What will the Pro plan include?
The personal finance dashboard (budget, net worth, debts and investments), company profiles with the data already gathered, the stock comparison tool and fundamental analysis with automatic data, AI-powered analysis of your portfolio, historical ratios and an ad-free site. Manual analysis stays free: what Pro adds is saving you the work of finding and organising the data.
What is the open beta?
Some features that will be part of Pro, such as the stock comparison tool and automatic data in the fundamental analysis, are open and free while we finish building them. They are marked with a "Pro · Beta" label. We will give advance notice before anything changes.
Where should I start if I want to learn finance from scratch?
An order that works: first an emergency fund and the 50/30/20 rule to organise your budget; then compound interest and inflation to understand why investing matters; then what an ETF is and how to build a diversified portfolio. Every Academy guide links to the next one and to the calculator that lets you test it with your own numbers.
Do the calculators work outside Spain?
Yes. The formulas (loan payments, compound interest, rental yield, company ratios) are universal and you can enter your own figures. The tax articles, however, explain Spanish rules unless stated otherwise.
Where does the stock comparison data come from?
From Yahoo Finance, cached for up to an hour. Metrics cover the trailing 12 months and each company is shown in its own currency. Data may be delayed or contain errors, so check it against the company's own reports.
Does FinSimLab provide financial advice?
No. FinSimLab is an educational tool and never constitutes financial, investment, legal or tax advice. It is not regulated by any financial authority (SEC, FCA, CNMV or others). For real investment decisions, consult a qualified adviser.
How are the calculations done?
The mortgage and loan calculators use standard amortisation; the real estate calculator computes NOI, cash flow, cap rate, cash on cash, IRR and NPV; compound interest applies periodic compounding with contributions; and the stock analyser uses fundamental ratios (P/E, P/B, ROE, debt/equity, margins and dividend) with a scoring system.
Where is my data stored?
On no server: calculations run in your browser and what you enter is saved only on your own device so you do not lose it when you come back. We do not ask for registration or personal data. See the Privacy Policy for details on analytics and cookies.