About Simple Finance Calculators

Real humans keeping your rent vs buy, mortgage, and Airbnb math current.

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Our Mission

Simple Finance Calculators exists to unlock financial knowledge for anyone making a housing decision. We read the same mortgage releases, rent indexes, and short-term rental reports that professionals rely on and translate them into interactive tools that feel approachable, transparent, and bias-free. Our mission is to keep every calculator honest with clear assumptions, cite the sources that inform our defaults, and update the math the moment new data is published so families, investors, and advisors can make smarter choices together.

Data Sources & Methodology

Every calculator calls out the data it uses. The core references refreshed monthly include:

Formulas are reviewed quarterly and whenever regulators update lending rules or tax guidance.

Update Cadence

Rent vs Buy Calculator

Last updated: November 2025

Latest change: added breakeven insights aligned with BLS rent CPI.

Mortgage Calculator

Last updated: November 2025

Latest change: refreshed PMI handling per HUD 2025 guidelines.

Airbnb ROI Calculator

Last updated: November 2025

Latest change: included AirDNA ADR averages and management fee presets.

Explore the Calculators

Jump directly into the tools that match your next decision.

Rent vs Buy Calculator

Model your breakeven year with side-by-side rent and ownership costs.

Mortgage Calculator

Visualize principal, interest, and payoff timelines with escrow costs.

Airbnb ROI Calculator

Stress-test nightly rates, occupancy, and management fees before purchasing.