15-Year vs. 30-Year Mortgage
Compare the two most common loan terms side by side — total interest paid, monthly payment difference, payoff timeline, and the exact dollar amount saved by choosing a shorter term.
How to Use the 15-Year vs. 30-Year Calculator
Getting your side-by-side comparison takes under a minute. Enter three numbers and the calculator handles the rest — showing you total interest, monthly payment difference, equity growth over time, and a full amortization schedule for both loans.
Enter Your Loan Amount
Input the amount you plan to borrow — not the home’s purchase price. If you know your down payment, subtract it from the home price to get the loan amount. The calculator uses this figure to compute the exact monthly payment and total interest cost for both loan terms simultaneously.
Enter the 30-Year Rate (Loan A)
Add the interest rate you’ve been quoted for a 30-year fixed mortgage. If you don’t have a formal quote yet, use the current national average as a starting point — you can refine it later. The 30-year rate is typically 0.5–0.75% higher than the 15-year rate for the same borrower profile and lender.
Enter the 15-Year Rate (Loan B)
Add the interest rate for the 15-year fixed term. Lenders price 15-year loans lower because the shorter repayment window reduces their risk. If you don’t have a 15-year quote, try subtracting 0.5–0.75% from your 30-year rate as an estimate — then get a formal quote to refine the comparison.
Read the Results & Download the Report
The results panel updates instantly — showing total interest saved, monthly payment difference, balance-over-time chart, and principal-vs-interest stacked comparison. Download the 3-page PDF to take to your lender: it includes the full comparison table, 6 summary cards, and complete month-by-month amortization schedules for both loans.
What This Calculator Shows You
Most mortgage comparison tools show you two monthly payment numbers and stop there. This calculator gives you the complete picture — total cost over the life of both loans, equity building speed, interest breakdown charts, and a professional report to take to your lender.
Total Interest Saved — Green Hero Card
The results panel leads with the single most important number: exactly how much total interest you save by choosing the 15-year term over the 30-year. On most $300,000–$500,000 loans, this figure exceeds $150,000 — and it updates in real time as you adjust rates or loan amount.
Monthly Payment — Both Loans, Side by Side
See the exact monthly P&I payment for the 30-year and 15-year term, plus the precise extra monthly cost of choosing the shorter term. This extra amount is the central trade-off — and comparing it to the total interest saved is the core of this decision.
6-Card Summary Grid
At-a-glance summary cards cover monthly payment for 30yr, monthly payment for 15yr, extra monthly cost, total interest for 30yr, total interest for 15yr, and total savings — colour-coded and labeled so you can read the full comparison in seconds without digging through a table.
Loan Balance Over Time — Dual-Line Chart
An area line chart plots the remaining balance of both loans year by year on the same axis. The 15-year line drops steeply and hits zero at year 15; the 30-year line descends gradually over three decades. This visual is often the most persuasive argument for the shorter term — seeing the gap is more impactful than reading the numbers.
Principal vs. Interest — Stacked Bar Chart
A stacked bar chart shows how much of the total amount paid for each loan goes toward principal versus interest. The contrast between the two bars makes immediately visible how much more of a 30-year loan’s total cost is pure interest — and how efficiently a 15-year mortgage allocates each dollar paid.
3-Page PDF with Full Amortization Tables
Download a professionally formatted PDF with the hero savings card, comparison table, 6 summary cards, and complete month-by-month amortization schedules for both loans — with annual rows highlighted for easy scanning. Page 2 covers all 360 months of the 30-year loan; Page 3 covers all 180 months of the 15-year loan.
15-Year vs. 30-Year — By the Numbers
How Different Buyers Use This Calculator
Your mortgage decision depends heavily on your life stage, income stability, and financial goals. Here’s how three common buyer profiles approach the 15-year vs. 30-year comparison — and what each should focus on in the results.
The First-Time Buyer
Balancing payment size vs. total costYou’re buying your first home and want to understand the real long-term cost of each option before committing. The 30-year payment looks more manageable right now — but you want to know exactly what you’re giving up in total interest before you decide.
- Start by comparing the monthly payment difference — is the extra amount genuinely unaffordable, or just uncomfortable?
- Look at the total interest saved figure and divide it by your extra monthly cost to see how many months it takes to “earn back” each dollar
- Use the balance chart to visualise how quickly each loan builds equity — relevant if you plan to sell or access equity in 7–10 years
- Download the PDF and take it to your lender to ask about qualification for both terms before deciding
The Pre-Retirement Planner
Wants to own outright before stopping workYou’re 45–55 and want to be completely mortgage-free before retirement. A 30-year loan taken now would still have a balance when you’re 75–85 — a problem. A 15-year loan gets you there by 60–70, with no housing debt affecting your fixed-income budget.
- Enter your actual loan amount and current quotes — see whether the 15-year payment fits within your pre-retirement income
- Check the balance chart for year 15: the 15-year loan is paid off; the 30-year still carries roughly 65% of the original balance
- Compare the total interest paid: every dollar saved goes directly toward retirement security instead of the lender’s pocket
- If the monthly difference is too large, explore a 20-year term with your lender as a middle ground
The Cash Flow Optimiser
Weighing mortgage cost vs. investment returnsYou’ve been told to “invest the difference” between the 15-year and 30-year payment instead of taking the shorter term. You want to understand both sides of this argument — the guaranteed interest savings versus the potential investment upside of keeping a lower payment.
- Note the exact extra monthly cost of the 15-year loan — this is the monthly amount you’d “invest instead” with a 30-year mortgage
- The 15-year saves interest equal to your mortgage rate, guaranteed and risk-free — compare this to your realistic long-term return after tax
- Factor in that the 30-year rate is higher — you’re paying more interest per dollar of balance, which affects the “invest the difference” math
- There is no universal right answer: the decision depends on your tax bracket, investment discipline, and risk tolerance
6 Things to Know Before Choosing Your Loan Term
The 15-year vs. 30-year decision affects your finances for decades. These six considerations will help you weigh the trade-offs accurately — before you sign anything.
Get Formal Quotes for Both Terms Before Comparing
The rate difference between a 15-year and 30-year loan from the same lender can vary significantly. Request a Loan Estimate for both terms simultaneously — using a single rate assumption for both (like subtracting a flat 0.6%) will give you a less accurate picture than two real quotes. This calculator is most useful when the rates you enter reflect actual lender offers.
Don’t Choose the 15-Year If It Strains Your Emergency Fund
The most common mistake buyers make is stretching to the 15-year payment at the expense of their emergency fund or retirement contributions. Financial planners widely recommend maintaining 3–6 months of expenses in liquid savings regardless of mortgage choice. If the higher 15-year payment would deplete this buffer, the 30-year with extra payments may be a safer path to the same outcome.
The 30-Year With Extra Payments Is Not the Same as a 15-Year
Even if extra payments on a 30-year loan produce the same payoff timeline as a 15-year loan, you’ll still pay the higher 30-year interest rate on every dollar of the remaining balance throughout the loan. The rate difference alone — typically 0.5–0.75% — can cost $30,000–$60,000 in additional interest over the same 15-year payoff window. A true 15-year mortgage locks in the lower rate from day one.
Consider How Long You Actually Plan to Stay in the Home
If you plan to sell in 5–7 years, the total interest saved over 15 versus 30 years is irrelevant — you won’t be in the loan long enough to realise it. What matters in a short holding period is the equity you build in those years, and whether the lower 15-year balance produces enough additional sale proceeds to justify the higher monthly payment. Use the balance chart to see the equity gap at your expected sale date.
PMI Does Not Apply to Loan Term — Only Down Payment
Private mortgage insurance (PMI) is triggered by loan-to-value ratio — specifically, a down payment below 20% — not by your choice of 15-year or 30-year term. Both loan terms carry PMI if your down payment is under 20%. However, a 15-year loan reaches 20% equity faster through principal paydown, so PMI cancellation may come sooner — typically 2–4 years earlier than a comparable 30-year loan.
The Tax Deductibility of Mortgage Interest Affects the Net Savings
If you itemize deductions, mortgage interest is tax-deductible — meaning the effective cost of your interest is lower than the stated rate. Because a 30-year loan generates more deductible interest, switching to a 15-year loan reduces your deduction. However, since the 2017 Tax Cuts and Jobs Act roughly doubled the standard deduction, fewer than 10% of U.S. taxpayers now itemize — making this consideration less relevant for most borrowers. Consult a tax advisor if this applies to your situation.
15-Year vs. 30-Year Mortgage — FAQ
Real questions from U.S. home buyers weighing these two loan terms — answered plainly.
Important disclaimer: All calculations provided by this tool are for educational and estimation purposes only and do not constitute financial, legal, or mortgage advice. Results are based on standard fixed-rate amortization formulas and assume a fixed interest rate for the full loan term, consistent monthly payments, and no prepayment, origination fees, escrow, property taxes, or homeowners insurance. Actual loan costs vary by lender, credit profile, loan program, and individual borrower circumstances. Monthly payment figures shown reflect principal and interest only — your total monthly housing cost will be higher when taxes, insurance, HOA fees, and PMI (if applicable) are included. Always obtain a formal Loan Estimate from a licensed lender and consult a licensed mortgage professional or financial advisor before making any borrowing decisions. HomeExpertly is not a lender, broker, or financial advisor.