Finance calculators
Loans, mortgages, interest, and retirement numbers worked out in the open. Every tool shows its formula, updates live, and works on any device.
Saved & recent
- Compound Interest CalculatorGrow a starting balance plus recurring deposits: future value, total interest earned, and growth multiple with monthly, quarterly, or annual compounding — formula shown.→
- Everyday Money CalculatorProrated rent, income-based splits, debt payoff timelines, debt-to-income, simple vs compound, and inflation — everyday money math with the rules shown.→
- Loan & Investing CalculatorTwenty-seven lending and investing formulas behind one dropdown: loan payments and comparison, EMI, interest-only and balloon loans, credit-card payoff, refinance break-even, home affordability, annuity future/present value and payouts, CD maturity, the rule of 72, real return, CAGR, NPV, IRR, payback, and dividend, P/E, and bond yields — each result shows the formula with your numbers substituted in.→
- Loan Amortization CalculatorLoan amortization made visible: the month-by-month principal and interest split, running balance, and what extra monthly payments save in interest and payoff time.→
- Mortgage CalculatorEstimated PITI mortgage payment: principal and interest plus property tax, insurance, and PMI under 20% down — the standard amortization formula, shown.→
- Retirement Savings CalculatorProject your retirement nest egg from current savings and monthly deposits, compare it with the 25× target for your desired income, and see the deposit needed.→
- Savings Goal CalculatorWork backwards from a savings target and deadline to the exact monthly deposit, netting what current savings and interest already cover — shortfall math shown.→
How this manual is organized
Each entry above opens a one-page tool: inputs on the left, the live result on its color board, and beneath the card the formula with worked examples and the method's limits. Save the tools you use often — they'll wait on this shelf next visit.