Calculate monthly mortgage payment, total interest paid, and full amortization summary.

Returns the monthly principal+interest payment, total interest over the loan life, total cost of the home, break-even analysis, and the first 12 months of amortization. Optionally includes property tax and insurance in the total monthly cost.

Compare total cost of renting vs buying over a given number of years.

Accounts for mortgage payments, equity built, opportunity cost of down payment, rent increases over time, and home appreciation. Returns which option is cheaper and by how much over the analysis period.

Project investment growth with compound interest and optional regular contributions.

Shows final value, total contributions, total interest earned, and a year-by-year growth table. Uses the standard compound interest formula with optional periodic contributions.

Calculate your FIRE (Financial Independence, Retire Early) number and timeline.

Finds the portfolio size needed to cover your expenses indefinitely using the chosen withdrawal rate. If you provide current savings and annual savings rate, also estimates how many years until you reach FIRE.

Calculate the real (inflation-adjusted) return on an investment.

Shows the difference between nominal growth and actual purchasing power growth. Useful for understanding if your investments are truly beating inflation.

Compare two loan options by total cost, monthly payment, and true APR.

Helps decide between a lower rate with higher fees vs higher rate with lower fees, or shorter term (higher payment, less interest) vs longer term (lower payment, more interest).

Find the true total cost and implied APR of any credit product.

Works for car financing, buy-now-pay-later, credit card minimum payments, personal loans, and any fixed payment schedule. Cuts through misleading '0% financing' or low-rate marketing to show actual cost.

Calculate how long to pay off a debt and how much interest you'll pay.

Compares the base payment plan vs adding extra monthly payments, showing exactly how many months and dollars you save.