Mortgage Payoff Calculator – Save Years with Extra Payments

Calculate how much time and interest you save by making extra mortgage principal payments.

🏠 Finance📐 Months saved = n - (-ln(1-P*r/M') / ln(1+r))
Current loan balance ($)
Interest rate (%)
Remaining term (years)
Extra monthly payment ($)
Please enter valid values.

Formula & Reference

VariableFormulaUnits
Mortgage Payoff Calculator – Save Years with Extra PaymentsMonths saved = n - (-ln(1-P*r/M') / ln(1+r))months saved

Step-by-Step Examples

Example 1
$280K, 6.5%, 25yr, +$200/mo

Extra $200/month.

  • Time saved: ~6 years | Interest saved: ~$73,000
✓ Save 6 years / $73K
Example 2
$200K, 7%, 20yr, +$100/mo

Extra $100/month.

  • Save ~2.5 years and ~$25,000 in interest
✓ Save 2.5 years
Example 3
+$500/mo

$280K, 6.5%, 25yr.

  • Save 10+ years and $130K+ in interest
✓ Save 10 years

Real-World Applications

Common Mistakes to Avoid

⚠️
Making extra payments occasionally

Consistency is key. Regular $100/month beats sporadic lump sums.

⚠️
Not specifying PRINCIPAL ONLY

Always designate extra payment as PRINCIPAL ONLY, or servicer may apply it as an advance payment.

Frequently Asked Questions

Extra payment vs investing?
If mortgage is 6.5% and stocks return 7%+, investing may win mathematically. Paying down mortgage is a guaranteed return. Personal preference matters.
How to make extra payments?
Specify PRINCIPAL ONLY online or by check. Or pay biweekly (26 half-payments = 13 full payments per year).
Refi vs extra payments?
Rate drops 1%+: usually refinance. Rate drop under 1%: extra payments may be simpler and nearly as effective.

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