Student Loan Refinancing Savings Calculator
Calculate how much you save by refinancing your student loans to a lower interest rate.
See reduced monthly payments and total interest saved.
What refinancing actually does
Refinancing replaces your existing loan(s) with a new private loan at a lower interest rate (or different term, or both). The new lender pays off your old loans; you now owe the new lender on new terms. The point is reducing total interest paid over the life of the loan, lowering monthly payment, or both.
The monthly payment formula
M = P × [r(1+r)^n] ÷ [(1+r)^n − 1]
Where P = principal, r = monthly rate (annual ÷ 12), n = number of monthly payments. This is the same amortization formula used for mortgages and car loans.
Worked example
$45,000 balance, current rate 7.5%, 10 years remaining vs refinanced at 5.0% over 10 years:
| Current (7.5%) | Refinanced (5.0%) | Difference | |
|---|---|---|---|
| Monthly payment | $534 | $477 | $57/mo less |
| Total payments (10 yr) | $64,077 | $57,261 | $6,816 less |
| Total interest | $19,077 | $12,261 | $6,816 saved |
The 2.5-percentage-point cut saves nearly $7,000 over the life of the loan. The break-even on most refinances happens within 1-2 years if there are no fees, because there’s no closing-cost equivalent like there is on a mortgage refinance.
The federal-to-private warning is genuinely important
This is the part that’s far more important than the math. Refinancing federal student loans (Direct Loans, Stafford, Perkins, PLUS) into a private loan permanently eliminates:
- Income-Driven Repayment (IDR) plans — SAVE, IBR, PAYE, ICR. Cap monthly payments at 5-15% of discretionary income
- Public Service Loan Forgiveness (PSLF) — full balance forgiven after 120 qualifying payments while working in qualifying public/non-profit jobs
- Teacher Loan Forgiveness — up to $17,500 for eligible teachers
- Federal forbearance — pause payments during financial hardship, unemployment, military service
- Federal deferment — pause for in-school enrollment, economic hardship, military service
- Death and disability discharge — federal loans typically discharged if borrower dies or becomes permanently disabled
- Future federal forgiveness programs — Biden’s various forgiveness attempts, future Congressional action
Once you refinance federal into private, none of this is recoverable. The decision is one-way.
When refinancing federal loans makes sense
- High income, stable career, no realistic PSLF path
- Current federal rate well above market private rates (typically 6%+ federal vs 4-5% private offer)
- High credit score (720+) qualifying for the best private rates
- Comfortable emergency fund covering 6+ months
- No plan to enter public service, non-profit, or teaching career
- Long enough remaining term that the interest savings exceed federal program value
When refinancing federal loans is a serious mistake
- Working in or planning to work in qualifying PSLF jobs
- Income that fluctuates dramatically (commissioned sales, freelance, gig economy)
- Pre-medical, pre-dental, or other long-training careers
- Possibility of returning to school
- Income below ~$75k and balance above ~$50k (IDR forgiveness math often beats refinancing)
- Currently using IDR successfully
Refinancing private-to-private is straightforward
Private student loans have none of the federal protections. Refinancing one private loan into another at a lower rate is essentially the same decision as refinancing a car loan or any other private debt. The math is pure interest savings minus fees.
Where to shop
Major student loan refi lenders (2024 rates):
| Lender | Variable | Fixed |
|---|---|---|
| SoFi | 5.5 to 9.8% | 5.0 to 9.5% |
| Earnest | 5.6 to 9.7% | 5.2 to 9.7% |
| Laurel Road | 5.5 to 10.0% | 5.4 to 9.9% |
| Credible (marketplace) | 5.5 to 9.0% | 5.0 to 9.5% |
| ELFI | 5.6 to 9.5% | 5.0 to 9.5% |
| Splash Financial | 5.5 to 10.0% | 5.0 to 9.9% |
Always get quotes from 3-5 lenders. Rate variation is significant between lenders for the same borrower profile.
The credit pull dance
Reputable lenders offer pre-qualification via soft credit pull — no impact on your credit score. Get pre-qualified at 3-5 lenders first, compare actual offers (not advertised rate ranges), then accept the best. The hard credit pull only happens when you formally accept.
If you submit formal applications at multiple lenders within a 14-45 day window (depending on credit scoring model), they’re typically counted as a single hard inquiry for credit scoring purposes. So rate-shopping doesn’t substantially hurt your score.
Variable vs fixed rate
Variable rates start lower (typically 0.5-1.5% below fixed for the same lender) but can rise. As of 2024 with the Fed at elevated levels, variable rates aren’t dramatically below fixed — many borrowers choose fixed for the certainty.
Variable makes sense if you plan to pay the loan off aggressively (3-5 years). Over a long term (10+ years), fixed is usually safer.
Term length affects total interest
Shorter terms have higher monthly payments but dramatically less total interest. Same $45,000 at 5%:
| Term | Monthly | Total interest |
|---|---|---|
| 5 years | $849 | $5,937 |
| 7 years | $635 | $8,372 |
| 10 years | $477 | $12,261 |
| 15 years | $356 | $19,047 |
| 20 years | $297 | $26,275 |
Going from 10-year to 5-year saves $6,300 in interest. Going from 10-year to 20-year adds $14,000 in interest. The temptation to lower the monthly payment by stretching the term is expensive.
Refinancing with a cosigner
If your credit is borderline or income is low, adding a cosigner (typically a parent) can drop your rate by 1-3%. Most lenders allow cosigner release after 24-48 months of on-time payments, freeing the cosigner once you’ve established a payment history on the loan.
The bottom line
For private student loans: refinance whenever rates drop enough to save meaningfully (typically 1+ percentage points). For federal loans: tread carefully — the federal protections are valuable and impossible to get back once given up. The cheapest interest rate isn’t necessarily the best deal when factoring in the optionality you lose.