Plain-English money math.

PITI breakdown, extra-principal payoff, shareable scenario URLs. Built around the math of paying down a mortgage faster.

Snowball + avalanche on multiple debts. See your debt-free date, total interest, payoff order. CSV download.

Financial independence / retire early. Your FIRE number (4% rule), years to FI, progress, and a real-return projection.

Watch a starting balance plus monthly contributions grow. Daily/monthly/annual compounding, effective APY, year-by-year table.

Set a goal + deadline to get the monthly amount you need — or set a monthly amount to see the timeline. Interest included.

Car, personal, and student loans — monthly payment, total interest, full amortization schedule, extra-payment savings, CSV.

Convert annual salary to hourly, weekly, biweekly, semi-monthly, and monthly pay — and back. Adjust hours/week and weeks/year.

Return on investment, net gain, return multiple, and annualized return (CAGR) from a start and end value.

Should you refinance? Monthly savings, break-even on closing costs, and lifetime interest net of costs — catches the term-reset trap.

How inflation erodes buying power: future cost, future buying power in today's dollars, and total inflation at any assumed rate.

Convert APR to APY (effective annual yield) and compare compounding frequencies side by side, with yearly interest on any balance.

Add sales tax to a price or pull it out of a tax-inclusive total. Works for sales tax, VAT, and GST at any rate.

Tip amount, total, and per-person split for any bill. 15/18/20/25% presets or a custom rate.

Final price after a percent-off, the amount saved, and the true effective rate when discounts stack.

How much house you can afford from income, debts, down payment, and rate — using the 28/36 DTI rule, with the limiting ratio shown.

Project your 401(k) balance with employer match, contribution rate, and return. See exactly how much the match adds.

Months to clear a card balance, total interest, and the minimum-payment trap laid bare versus a fixed payment.

Maturity value and interest on a certificate of deposit from your deposit, APY, and term.

How big your safety net should be (3–12 months of expenses), the gap to your target, and how long to get there.

How long your savings last at a given withdrawal and return, with inflation-adjusted withdrawals — or whether it's sustainable.

The monthly income a lump sum provides over a set term at a given return, plus total payout and interest earned.

Annual, quarterly, and monthly income from a dividend yield, plus a DRIP reinvestment projection.

Interest and total from principal, rate, and time (I = P×r×t), with a side-by-side compound comparison.

Split your take-home pay with the 50/30/20 rule (needs/wants/savings) or your own percentages, with a visual breakdown.

Rental property cap rate, NOI, monthly cash flow, and cash-on-cash return from price, rent, expenses, and financing.

Months of cash left from your burn rate, your zero-cash date, and whether you're default alive.