Calculadora de Pagamento Extra — Formula
## Impact of Extra Mortgage Payments
Extra payments applied to principal reduce the balance faster, saving interest and shortening the loan term.
### New Payoff Formula
**New Months = log(PMT / (PMT - P x r)) / log(1 + r)**
Where PMT is the total monthly payment (base + extra), P is the loan balance, and r is the monthly rate.
### Why Extra Payments Are So Effective
- Early in a mortgage, most of each payment goes to interest
- Extra principal reduces the balance that accrues interest
- The effect compounds: less interest means more of future payments go to principal
- Even small extra amounts make a significant difference over decades
### Strategies
- Round up to the nearest hundred
- Apply annual bonuses or tax refunds
- Match extra payments to raises or eliminated expenses
Extra payments applied to principal reduce the balance faster, saving interest and shortening the loan term.
### New Payoff Formula
**New Months = log(PMT / (PMT - P x r)) / log(1 + r)**
Where PMT is the total monthly payment (base + extra), P is the loan balance, and r is the monthly rate.
### Why Extra Payments Are So Effective
- Early in a mortgage, most of each payment goes to interest
- Extra principal reduces the balance that accrues interest
- The effect compounds: less interest means more of future payments go to principal
- Even small extra amounts make a significant difference over decades
### Strategies
- Round up to the nearest hundred
- Apply annual bonuses or tax refunds
- Match extra payments to raises or eliminated expenses
Exemplo Resolvido
A $300,000 loan at 7% for 30 years with an extra $300/month.
- Base payment: $1,995.91
- Total payment with extra: $1,995.91 + $300 = $2,295.91
- Original payoff: 360 months (30 years)
- New payoff: approximately 263 months (about 22 years)
- Months saved: 360 - 263 = 97 months (about 8 years)
- Original total interest: $418,528
- New total interest: approximately $303,726
- Interest saved: approximately $114,802