All calculators

Use each tool when the decision matches the one-liner. Compare two paths from a playbook when you need a verdict, not just a payment.

Every calculator page states how the number is built and what the model leaves out — state tax, lender overlays, fees, or sequence-of-returns risk, depending on the tool. Math lives in shared libraries so a compare and a single-path calculator cannot drift. IRS and SSA figures are dated on the This year pages; confirm against the official notice if you are filing.

These are educational estimates, not a filed return, a pre-approval, or investment advice. Read the matching guide when you want the arithmetic in prose, then change the inputs until the result matches the decision in front of you.

Tax

Federal taxTaxYou want a federal refund / owed estimate before you file.Take-home payTaxYou know salary and want what actually hits the bank.Itemize vs standardTaxYou have mortgage interest, SALT, or charity and are unsure which deduction wins.

Home

Mortgage paymentHomeYou have a price, rate, and term and want the monthly housing number.Mortgage approval estimateHomeYou are shopping and need a ceiling before you tour.Refinance break-evenHomeYou have a lower-rate offer and want months to recoup closing costs.

Investing

Savings & investment growthInvestingYou want a future balance from contributions and a return assumption.IRA & 401(k) contributionInvestingYou are setting deferrals and need this year’s limit and match.HSA contribution limitsInvestingYou have an HDHP and want remaining HSA room including employer money.FIRE numberInvestingYou want a back-of-the-envelope years-to-FI from spend and savings.

Loans

Loan paymentLoansYou have amount, APR, and term for an auto or personal loan.

Debt

Debt payoffDebtYou can pay extra and want months saved versus minimums.

Planning

Budget 50/30/20PlanningYou have take-home pay and want a simple spending split.Emergency fundPlanningYou are building cash before investing extra.Future inflationPlanningYou want today’s dollars in a future year’s prices.Net worthPlanningYou want a single snapshot of assets minus debt.