Money decisions, actually decided.

14 deep calculators for the money decisions that matter — each one doesn’t just compute, it gives a reasoned, conditional recommendation with every assumption shown, sourced, and editable. Computed in your browser. Nothing to sell you.

14 calculators · no accounts · nothing to sell

It recommends — not just computes

Most calculators hand you a number and leave. Ours reads the number and tells you what to do, with the conditions that would change the answer.

It sells nothing

No products, no lead-gen, no pay-to-rank. The recommendation is computed and published before any link is ever sought — so who pays can never move it.

It shows its work

Every assumption is visible, sourced, and editable; every formula is on the page. A model based on your numbers — a scenario projection, not a forecast.

Calculators for every money decision

Pick the decision you’re facing. Every one is live, free, and runs in your browser — no sign-up.

Decision guides

Prefer to read it through first? Each guide walks one money decision with worked numbers and charts, then hands you the calculator.

Housing Rent vs. Buy: When Does Buying Actually Win? Renting is not throwing money away. The real comparison is buying versus renting and investing the difference, and it has a crossover year. Read the guide → Housing How Much House Can You Afford? The Guideline Number and the Lender's Maximum The same income supports two very different prices: the one a 28/36 guideline allows and the one conventional debt-to-income limits allow. See both, and what the payment must cover. Read the guide → Housing Prepay the Mortgage or Invest? The Break-Even Return Extra principal pays a guaranteed return; investing pays an expected one. The break-even return is where the answer changes, and total interest saved is not the number that finds it. Read the guide → Debt & borrowing Why Your Credit Card Takes So Long to Pay Off, and What an Extra $50 Changes A fixed-payment comparison shows how another $50 changes the payoff term and total interest, and why the statement minimum is a different calculation. Read the guide → Debt & borrowing Why Your Student Loan Balance Can Grow While You Pay Every Month A calculated monthly payment can fall below accrued interest. See how negative amortization changes the amount owed and why capitalization is a separate event. Read the guide → Debt & borrowing Highest Interest Rate or Snowball? What Choosing the Order Costs Both orders on one set of balances: the interest the choice is worth, how much larger the monthly payment effect is, and what the evidence says about finishing. Read the guide → Investing & priorities Where Should Your Next Dollar Go? The Order of Operations for Extra Money The order to fund things in, and the return on each step, from the 401(k) match down to the mortgage. Read the guide → Retirement & goals Are You on Track to Retire? Start With Spending, Not Salary Compare the balance your saving pattern could produce with the balance your spending plan requires, then test the assumptions that decide the result. Read the guide →

All decision guides →

Not a bare number — a reasoned, conditional recommendation. Flip through a few:

Computed in your browser — no accounts, and calculator entries aren’t sent.

Every figure sourced and dated; every formula shown.

The recommendation can’t be changed by who pays.