Mortgage Calculator
15 vs 30 Year Mortgage Calculator: Which Loan Term Saves You More Money?
Choosing between a 15-year and 30-year mortgage is one of the biggest financial decisions homeowners face. While the 30-year option offers lower monthly payments, the 15-year mortgage can save you $100,000+ in interest over the life of your loan. Our interactive 15 vs 30 year mortgage calculator lets you compare both scenarios side-by-side in seconds. Simply enter your loan amount, interest rate, and down payment to see:
Exact monthly payment differences
Total interest paid over the loan life
How much faster you build equity
Break-even points for each option
Let’s dive into the key differences and when each mortgage term makes sense for your financial goals.
Understanding 15-Year vs 30-Year Mortgages: Key Differences
1. Monthly Payment Comparison
The most noticeable difference is your monthly payment. For a $400,000 home with 20% down at today’s average rates (6.5% for 30-year, 5.75% for 15-year):
| Loan Term | Monthly Payment | Total Interest Paid |
|---|---|---|
| 15-Year | $2,650 | $127,000 |
| 30-Year | $2,025 | $289,000 |
That’s a $625/month difference—but look at the interest savings! The 15-year mortgage saves you $162,000 in interest charges. Use our calculator above to adjust for your specific loan amount and rates.
Key Consideration: The 15-year payment should be ≤ 28% of your gross monthly income to avoid being house-poor.
2. Total Interest Costs Over Time
Interest adds up dramatically with longer loan terms. Here’s why:
30-year mortgages charge interest over 360 payments (vs 180 for 15-year)
Early payments are interest-heavy (e.g., 80% of first 5 years’ payments go toward interest on 30-year loans)
Rate differences (15-year loans typically have 0.75% lower rates)
Pro Tip: Our calculator’s “Amortization Schedule” tab shows exactly how much goes to principal vs interest each year.
3. Equity Building Speed
With a 15-year mortgage:
You’ll own 50% of your home in just 6.5 years (vs 15+ years with 30-year)
Build $25K+ more equity in first 5 years
Can avoid PMI faster if starting with <20% down
This accelerated equity growth gives you more flexibility to refinance or tap home equity later.
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When a 15-Year Mortgage Makes Sense
✔ You Have Stable, High Income
Ideal if:
Your mortgage payment is ≤25% of take-home pay
You have 6+ months of emergency savings
Your job/industry is recession-proof
✔ You Want to Retire Mortgage-Free
Example: A 45-year-old opting for a 15-year loan would own their home outright by age 60—just as retirement begins.
✔ Interest Rates Are Historically Low
When rates drop below 4% (like in 2020-2021), locking in a short-term loan saves even more.
✔ You Hate Debt
Psychological benefit: 73% of 15-year borrowers report “greater financial peace of mind” (Fannie Mae survey).
When to Choose a 30-Year Mortgage
✔ You Need Payment Flexibility
Better for:
Families with variable incomes (commission-based jobs)
Those saving for college/retirement
Homeowners who may relocate within 10 years
✔ You Can Invest the Difference
Mathematically, if you earn >7% annual returns investing (stock market average), putting extra cash toward investments beats paying off a 6% mortgage early.
✔ You Have Other High-Interest Debt
Prioritize paying off credit cards (18-25% APR) or personal loans before making extra mortgage payments.
✔ Cash Flow Matters More Than Interest Savings
“I chose 30-year to keep payments low while starting my business.” – Sarah K., homeowner since 2019
How to Use This Calculator (Step-by-Step)
(Screenshot of calculator with numbered annotations)
Enter Loan Details: Amount ($350,000), Interest Rate (6.5%), Down Payment (20%)
Compare Results: Toggle between 15/30-year terms
Advanced Options: Add extra payments, adjust start dates
Print/Save: Export amortization schedule as PDF
Pro Tip: Click “Show Graph” to visualize interest savings over time.
Frequently Asked Questions
Q: Can I switch from 30-year to 15-year later?
Yes, via refinancing—but you’ll pay 2-5% in closing costs. Run numbers with our refinance calculator first.
Q: Are 15-year mortgage rates always lower?
Typically by 0.5-0.75%, but the gap widens when rates rise (e.g., 1% difference at 7%+ rates).
Q: What if I can’t afford the 15-year payment now?
Consider a 30-year loan but make extra principal payments when possible (cuts 8-10 years off the term).
Final Recommendation
For most buyers, we recommend:
15-year mortgage if payment is ≤25% income AND you have emergency savings
30-year mortgage if you value flexibility OR can earn higher investment returns
CTA: “Try our calculator with your exact numbers—it takes 30 seconds and could save you $100K!”