Why is this free?
Because the math doesn't need to cost anything. We built the tool we wanted for our own properties, and there's no sign-up, no premium tier, and no ads. Your numbers never leave your browser, so there's nothing to monetize even if we wanted to.
How is this different from a regular mortgage calculator?
Most calculators handle a single loan and a single extra payment. PayoffRentals lets you model a whole portfolio, compares seven payoff strategies side-by-side, and shows how freed-up payments cascade from one mortgage to the next as each gets paid off.
What is the "Set Payment To" column?
It shows the exact monthly payment to set for each property based on the winning strategy. As properties get paid off, the extra money rolls to the next target, so these amounts update over time.
Is my data private?
Yes. Everything is stored locally in your browser — no accounts, no uploads, no servers. Clear your browser data and it's gone. Use Export Backup to save an encrypted-friendly JSON file you can re-import on another device.
Which payoff strategy is best?
It depends on your goals. Highest-interest-first saves the most money. Smallest-balance-first frees up cash flow sooner. The tool compares them with your actual numbers so you can see the difference.
Can I use this for just one property?
Yes. When you open the calculator, choose "Single Property" mode for a quick analysis of one mortgage. You can always switch to multi-property mode later.
What is the avalanche method?
The avalanche method directs all extra payments to the mortgage with the highest interest rate first. Once that one is paid off, the freed-up payment rolls to the next highest rate. It saves the most money overall.
What is the snowball method?
The snowball method pays off the smallest balance first for quick wins. As each mortgage is eliminated, its payment rolls into the next one, building momentum like a snowball.
Can I import my properties from a spreadsheet?
Yes. Click "Import Excel/CSV" on the Properties tab. The importer auto-detects column headers and handles most spreadsheet formats. You can also download a template to fill in.
Does this work on my phone?
Yes, the calculator is fully responsive and works on phones, tablets, and desktops. Your data is saved in your browser, so you can pick up where you left off.
How accurate are the results?
Very. We use the same amortization formulas your lender uses. Accuracy depends on the numbers you enter — grab the current balance and rate from your latest statement. Results are estimates for planning; your lender's exact payoff quote may vary slightly due to daily interest accrual. Always confirm with a tax or financial professional before making large prepayments.
Can I save or export my results?
Yes. The Export PDF tab generates a detailed report. You can also export your data as a backup file to import on another device, and the Schedule tab creates a printable payment schedule.
How do I use this tool?
Three steps: (1) Add your properties by clicking "Add Property" or importing from a spreadsheet. Each property needs a name, current balance, interest rate, and monthly payment. (2) Go to the Strategy tab and enter how much extra you can pay each month above your minimums. (3) Click "Run Analysis" to compare all 7 payoff strategies and see which saves you the most money and time.
What are the 7 payoff strategies?
Avalanche: Targets the highest interest rate first, saving the most money overall. Snowball: Pays off the smallest balance first for quick motivational wins. Highest Payment: Targets the biggest monthly payment first, freeing up cash flow fastest. Shortest Term: Focuses on the mortgage closest to payoff for quick portfolio reduction. Highest Cash Flow: Prioritizes the best-earning rental so you can reinvest income sooner. Even Spread: Splits extra payments evenly across all mortgages. Custom Priority: You choose the payoff order yourself.
Any tips for importing a spreadsheet?
The importer works with most Excel and CSV formats. It auto-detects column headers and handles various layouts. Your file should have columns for Property Name, Current Balance, Interest Rate, and Monthly Payment. Optional columns include Property Value, Loan Term, Rental Income, and Expenses. It automatically skips paid-off properties, HOA rows, and non-mortgage items. You can download a template from the Export & Data tab to get started.