Loan Calculator Estimate payments, interest, and payoff timelines — with extra payments, bi-weekly options, and amortizat...
Loan Calculator
Estimate payments, interest, and payoff timelines — with extra payments, bi-weekly options, and amortization schedules.
Amortization is the process of gradually paying off a loan through regular payments. Each payment covers:
- Interest: Calculated on the remaining balance (higher early on)
- Principal: The portion that reduces your debt (grows over time)
Example: $300K mortgage @ 6.8% for 30 years: • Payment 1: $1,699 interest, $251 principal • Payment 120 (10 yrs): $1,417 interest, $533 principal • Payment 360 (30 yrs): $11 interest, $1,939 principal
✅ Key Insight: Making extra payments early has the biggest impact — because you reduce the balance when interest is highest.
⚠️ Watch for these risky loan features:
- Negative Amortization: Payment < interest → balance grows (common in option ARMs).
- Balloon Payments: Small payments for years, then huge lump sum due.
- Precomputed Interest (Rule of 78s): Front-loads interest — no savings for early payoff.
- Teaser Rates: Low intro rate, then jumps 3–5% (common in personal loans).
- Prepayment Penalties: Fee for paying off early (check your contract!).
✅ Always ask: “Is this a simple interest loan? Are there prepayment penalties?”
| Loan Type | Average Rate | Notes |
|---|---|---|
| 30-Yr Fixed Mortgage | 6.8% | Freddie Mac, May 2025 |
| 15-Yr Fixed Mortgage | 6.0% | |
| Auto Loan (60-mo new) | 7.2% | Experian Q1 2025 |
| Auto Loan (60-mo used) | 10.5% | |
| Personal Loan (24-mo) | 12.5% | LendingTree avg. |
📉 Bi-Weekly Hack: Pay half-monthly payment every 2 weeks → 26 half-payments = 13 full payments/year → • $300K mortgage @ 6.8%: **7 years faster**, **$83,000 interest saved**
➡️ Standard Loan
See full amortization for mortgages, auto, or personal loans.
➡️ Interest-Only
Model HELOC draw periods or construction loans — then see the payment shock when amortization begins.
➡️ Bi-Weekly
Compare standard vs. bi-weekly — see years and interest saved.
➡️ Extra Payments
Test lump sums (tax refund, bonus) or recurring extra payments.
Note: Assumes fixed rate, no fees, and on-time payments. Adjustable-rate loans require scenario modeling.