Mortgage and investing tradeoff

Mortgage Payoff vs. Invest Calculator

Compare sending extra cash to mortgage principal with investing the same amount, while keeping the monthly outflow equal.

Use the unpaid principal balance.
Enter the note rate on the mortgage.
Leave blank to calculate the scheduled payment. Exclude taxes, insurance, mortgage insurance, and homeowners association dues.
The same amount is used in both strategies.
This is an assumption, not a guaranteed return.
Applied as a simple reduction to the assumed annual return.
Compare both strategies at the same future date.

Results will appear after valid values are entered.

Mortgage payoff effect

The extra-principal strategy sends the added monthly cash to the mortgage until it is paid off. After that, the model invests the amount that had been going to the mortgage so the two strategies keep the same total monthly outflow.

Scheduled monthly principal and interest Calculated or entered payment
Extra-principal payoff Estimated time saved
Mortgage interest saved Compared with the scheduled mortgage

Compare the same future date

Home value is left out because it is the same in both paths. The comparison uses investment value minus remaining mortgage balance. A positive difference means the modeled invest-first path is ahead at the selected horizon.

Pay extra principal

Investment balance
Mortgage balance
Net position

Invest the extra cash

Investment balance
Mortgage balance
Net position
Modeled difference At the selected comparison horizon
Net investment return assumed Expected return minus entered annual fees
Approximate break-even net return Modeled return where the two paths finish about even

What this estimate leaves out

Investment returns can vary widely and can be negative. The model uses a constant monthly return based on the annual assumption. It does not model market volatility, taxes, account contribution limits, employer matching, changes in mortgage terms, home-value changes, or transaction costs beyond the investment fee entered above.

Mortgage-interest tax treatment also varies by household and loan. Treat the result as a planning comparison, then adjust the assumptions for the account and mortgage you actually use.

For educational purposes only. Results are estimates. Review the Calculator Methodology for shared assumptions, rounding, payoff timing, and privacy-conscious analytics details.