Run the numbers before the numbers run you.

Compound interest is what happens when the interest your money earns starts earning interest of its own. This calculator compounds monthly, which matches how most savings and brokerage accounts actually credit growth. It assumes a constant annual return, which real markets never deliver in a straight line — treat the result as a planning estimate, not a guarantee.

Every fixed-rate loan uses the same amortization math: a level monthly payment covering both interest and principal, structured so the balance hits zero at the end of the term. Stretching the term lowers the monthly payment but almost always raises total interest paid.

The 50/30/20 split is a starting framework, not a rule: roughly 50% toward needs, 30% toward wants, 20% toward savings and extra debt paydown. High cost-of-living areas often need a heavier needs share; treat the output as a first draft.

This calculator starts from what you've already saved, adds your monthly contribution every month, and compounds any expected return along the way, showing a month count and an estimated calendar date.

A modest 2–3% annual inflation rate compounds the same way interest does — over 20–30 years it can cut purchasing power by half or more. This calculator shows what today's amount will need to grow to just to keep the same buying power, and what today's amount will feel like in future dollars.

Common guidance is three to six months of essential expenses, more for single-income households or less stable work. This calculator sets the target from your monthly essentials and coverage goal, then estimates how many months it will take to close the gap at your current savings rate.

Lenders typically cap debt-to-income around 36–43%. This calculator works backward from your income, existing debts, and chosen DTI ceiling to the monthly payment you could carry, then to an estimated loan amount and home price at your rate and term.

This combines a starting balance, ongoing monthly contributions, and compounding growth over the years between now and your target retirement age, using the same monthly-compounding math as the compound interest tool.

A more flexible cousin of the compound interest tool, aimed at brokerage accounts — it nets an annual fee or expense ratio out of the return before compounding, since even a small ongoing fee compounds against you the same way growth compounds for you.

Net worth is total assets minus total liabilities — a single snapshot number that's more useful tracked over time than judged in isolation. Add every asset you own and every debt you owe to see where you currently stand.

Minimum payments are calculated to keep balances outstanding as long as possible. This tool applies your fixed monthly payment against the balance at your card's APR each month until it hits zero, so you can see exactly how much interest a bigger payment saves.

Auto loans use the same amortization as mortgages, over a shorter term. The vehicle price minus your down payment and trade-in value is financed at a fixed rate over the loan's monthly term.