Volume I — the full index
The calculators.
All eighteen.
Every tool below runs in your browser. We never see what you type. Numbers come back instantly and link to a documented methodology.
- Indexed
- 18 tools
- Categories
- 3
- Affiliates
- 0
- Cost
- $0.00
Mortgage & housing
7 toolsMortgage Early Payoff Popular
How much interest extra payments save and how many years they cut from your loan.
Refinance Break-Even
When refinancing actually saves money — and how long it takes to break even on closing costs.
Rent vs Buy
The true total cost of renting vs buying over time, including the opportunity cost most calculators ignore.
How Much House Can I Afford
A realistic affordability number based on income, debts, and down payment — not the inflated one a bank will approve.
Biweekly Mortgage
How switching to biweekly payments quietly cuts years off your loan and saves five figures in interest.
Amortization Schedule
Every dollar of your monthly payment, broken into principal vs interest, month by month.
Mortgage Recast
Lower your payment with a lump sum and a $250 fee — no refinancing required.
Car & auto
6 toolsLease vs Finance vs Cash Popular
Which way to pay for a car wins on net wealth, accounting for HYSA opportunity cost, depreciation, and cash out.
Car True Cost of Ownership
Per-year and per-mile cost across depreciation, insurance, fuel, maintenance, registration, and repairs.
Auto Loan Early Payoff
Interest saved and months clipped by paying extra toward the principal each month.
Auto Refinance Break-Even
When auto refinancing actually pays — and the warning when fees outrun savings.
New vs Used Car
Same model, new vs three years old. The depreciation cliff and the HYSA growth you forgo by going new.
Car Trade-in Timing
The exact month when trading in beats keeping your old car, based on maintenance escalation and depreciation drag.
Debt & savings
5 toolsDebt Payoff Strategies
Compare avalanche vs snowball side by side. See which strategy clears the debt faster, and which leaves more in your pocket.
Extra Payment vs Investing
Pay down the mortgage or invest the difference? Monte-Carlo probability against your specific rate and time horizon.
Compound Interest
How compounding turns small contributions into life-changing balances — and what every year of delay actually costs.
Buy Now, Pay Later
The real cost of 'interest-free' installment plans once late fees and missed payments are priced in.
Minimum Payment Trap
How a $5,000 credit-card balance becomes $13,000+ when you pay only the minimum.
Editor's note
No accounts. No affiliate fees. No paid recommendations. Every calculator shows its methodology — verify the math yourself.