Two weeks ago I shared a collection of 6 financial calculators. The response was incredible, so I kept building.
Today, fi-calc.com has 25 completely free calculators covering every major personal finance need:
🏠 Housing
• Mortgage Calculator (full PITI + amortization schedule + pie chart)
• Rent vs Buy Calculator
• House Affordability Calculator
• Refinance Calculator
💰 Investing & Retirement
• Compound Interest Calculator
• Investment Return Calculator
• Future Value & Present Value Calculators
• ROI Calculator
• Retirement Savings Calculator
• 401(k) Calculator
• FIRE Calculator (Financial Independence)
💳 Debt & Loans
• Loan Comparison Calculator
• Auto Loan Calculator
• Student Loan Calculator
• Credit Card Payoff Calculator
• Debt Payoff Calculator (Avalanche method)
📊 Everyday Finance
• Budget Planner (50/30/20 rule)
• Savings Goal Calculator
• Inflation Calculator
• Salary & Take-Home Pay Calculator
• Net Worth Calculator
• Currency Converter (15+ currencies)
• CD Calculator
• Sales Tax Calculator
✨ Tech Stack
• Pure vanilla HTML/CSS/JS — no frameworks
• Chart.js for animated interactive charts
• Responsive design (mobile-friendly)
• All calculations run client-side in your browser
• No data collection, no accounts, no cookies
🔗 Give it a try: fi-calc.com
The entire site is free and open. I built it because I was tired of calculator sites with paywalls, signup walls, and bloated ad experiences.
Would love feedback from the community! What other calculators should I build next?
Top comments (1)
Solid range. The one I'd add is a forward-looking monthly cash-flow tool. Almost everything here answers a single-decision question (this mortgage, this loan, this goal), but the thing people actually struggle with day to day is "given my income, bills and savings, what can I safely spend this month before something breaks." It's less a calculator and more a small running projection, and it's the gap most of these tools leave.
The avalanche debt payoff and rent vs buy ones are the two I'd expect to get the most repeat use, since those are decisions people agonise over for weeks. I build a personal finance app in the same no-signup, no-bank-linking spirit, so the "just tools, no walls" approach really resonates. Nice work shipping 25.