Refinance Calculator Estimate savings, break-even point, and interest reduction for mortgage, auto, and student loan refi...
Refinance Calculator
Estimate savings, break-even point, and interest reduction for mortgage, auto, and student loan refinancing — with 2025 rates and fees.
Refinancing** = Replacing an existing loan with a new one — typically at a lower rate or better terms.
Key Formulas**:
- Monthly Savings** = Current Payment − New Payment
- Break-Even** = Closing Costs ÷ Monthly Savings
- Interest Saved** = Total Old Interest − Total New Interest
Example (Mortgage)**:
- $280K @ 6.8%, 25 yrs → $1,940/mo, $292K interest
- Refi to 5.8%, 30 yrs, $4,500 closing → $1,650/mo, $314K interest
- → $290/mo saved, but **+$22K interest** (longer term)
- → If keep 25-yr term: $1,820/mo, $229K interest → **$63K saved**
✅ Pro Tip**: Always compare *same-term* refis — extending term reduces payment but increases total interest.
⚠️ Avoid these costly mistakes:
- Extending term > original** — $300K loan: 30→40 yrs saves $120/mo but adds $76K interest
- Cash-out without plan** — Borrowing $30K for vacations → $174/mo + $31K interest
- Refinancing federal student loans** — Losing IBR, PSLF, forgiveness options
- “No closing cost” bait** — $0 fees = +0.25–0.5% rate → $10K extra interest over life
✅ When to Refinance**:
- Rate drop ≥1% (mortgage) or ≥2% (auto/student)
- Break-even <3 years (mortgage) or <1 year (auto)
- Improving credit score (700+ → qualify for best rates)
| Loan | Current | Refi | Savings | Break-Even |
|---|---|---|---|---|
| $300K Mortgage | 6.8% | 5.8% | $63K int | 2.1 yrs |
| $25K Auto | 10.0% | 5.25% | $2,100 int | 5 mos |
| $50K Student | 7.0% | 5.5% | $5,700 int | 0 mos |
📉 Cash-Out vs. HELOC**:
- Cash-out refi**: Fixed rate, higher closing costs, resets mortgage clock
- HELOC**: Variable rate, $0–$500 closing, interest-only for 10 yrs
➡️ Mortgage Refinance
“$280K @ 6.8% → 5.8% for 30 yrs” — see payment change, break-even, interest impact.
➡️ Auto Loan Refinance
“$18K @ 10% for 48 mos → 5.25% for 60 mos” — model term extension trade-off.
➡️ Student Loan Refinance
“$45K @ 7.05% → 5.5% for 15 yrs” — federal vs. private risk assessment.
Note: Uses 2025 avg. rates (mortgage 5.5–5.8%, auto 5.25%, student 5.5%), standard closing costs, and compound interest math.