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dayu2333-jinyul

Posted on • Originally published at financalcai.com

5 Free Financial Calculators I Built That I Actually Use Every Month

I built FinCalc AI after realizing I was maintaining the same Excel spreadsheets for years.

Mortgage Calculator

Most online calculators give you a monthly payment and call it done. This one shows the full amortization schedule. Bi-weekly payments save 4-5 years and ~$65K on a $400K mortgage at 6.5%.

Compound Interest Calculator

$500/month at 7% for 30 years = ~$610K. Wait 5 years to start = only ~$440K. That delay costs $170K.

Retirement Calculator

Monte Carlo simulation with 1000 random scenarios. The 4% rule has a ~5% failure rate over 30 years.

ROI Calculator

For evaluating side projects. Forces you to value your time at a real hourly rate.

Debt Payoff Calculator

Snowball vs avalanche comparison. Avalanche is mathematically optimal, snowball works better psychologically.

→ All free at financalcai.com. No signup, no email, works on mobile.

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