200
Short and intense, or long and flexible?
Home price, down payment, and both fixed rates — the full head-to-head.
X VS Y COMPARISON · MONEY
15-Year vs 30-Year Mortgage
The 15-year mortgage costs more every month but can save a six-figure sum in interest; the 30-year keeps payments low and flexible. Enter your price, down payment, and both rates to see both monthly payments, both interest totals, and exactly how much interest the shorter term erases.
What the comparison shows
On a $400,000 home with $80,000 down ($320,000 financed), a 15-year at 5.5% costs $2,615 a month while a 30-year at 6.5% costs $2,023 a month — a $592.05 monthly gap. The 15-year’s total interest is $150,640 vs $408,142 on the 30-year: the shorter term erases $257,502 of interest, about 63.1% of what the 30-year would cost you in interest alone. That is the whole trade: $592.05 more per month to kill $257,502 of interest.
Output · formula · meaning
| Output | Formula | What it means |
|---|---|---|
| Monthly payment (P&I) | loan × r(1+r)n ÷ ((1+r)n−1) | Principal + interest each month: $2,615 (15-yr) vs $2,023 (30-yr). |
| Total interest | payment × months − loan | Every dollar paid to the lender beyond principal: $150,640 vs $408,142. |
| Interest saved | 30-yr interest − 15-yr interest | What the shorter term erases: $257,502 (63.1% of the 30-year interest). |
| Monthly gap | 15-yr payment − 30-yr payment | The extra you pay each month for the shorter term: $592.05. |
Who uses this
- First-time buyers: can you actually afford the 15-year payment, or does the 30-year keep you safely under the 28% housing ratio?
- Refinancers: dropping from a 30-year to a 15-year at a lower rate — what the payment jump buys in interest destroyed.
- Early-retirement planners: a paid-off house by 55 vs maximum monthly flexibility — the numbers behind the philosophy.
- Move-up buyers: equity builds roughly twice as fast on the 15-year — check the five-year equity difference before you pick.
Accuracy & limitations
Principal and interest only: property tax, homeowners insurance, HOA dues, and PMI sit on top of both figures and don’t change the winner. Assumes fixed rates, no extra payments, and no refinancing. The rates are your inputs, not market quotes — get real quotes before deciding, and remember closing costs and the 15-year’s stricter income qualification.
Sizing up what you can afford? Read how much house you can afford or run the mortgage calculator for either term alone.
Cite this calculatorBright Side Kit. “15-Year vs 30-Year Mortgage.” brightoolbox.com, 2026.
Bright Side Kit. "15-Year vs 30-Year Mortgage." https://brightoolbox.com/15-year-vs-30-year-mortgage/ Accessed October 22, 2026.Frequently asked questions
Which is better, a 15-year or 30-year mortgage?
Neither wins outright — they optimize different things. The 15-year destroys interest (tens to hundreds of thousands of dollars) and builds equity fast, but the payment is much higher and the income qualification stricter. The 30-year buys flexibility: a lower required payment you can supplement with extra payments in good months. Affordability decides more often than math.
Can I afford the 15-year mortgage payment?
A common rule: keep total housing costs under 28% of gross monthly income. If the 15-year payment (plus tax and insurance) fits under that line with a comfortable emergency fund left over, the shorter term is a strong play. If it stretches you, the 30-year with occasional extra principal payments is the safer version of the same idea.
Why is the 15-year mortgage rate lower than the 30-year?
Lenders take less risk on shorter loans: inflation and rate changes have half as long to bite. The 15-year rate typically sits 0.5–1 percentage point below the 30-year — which compounds the savings, since you pay the lower rate on a loan that amortizes twice as fast.
Is a 30-year mortgage with extra payments the same as a 15-year?
Close, but not identical. Paying a 30-year off in 15 years via extra principal kills nearly the same interest — and you keep the lower required payment for hard months. The catch: the 30-year rate is higher, so the DIY version costs a bit more in interest, and it requires the discipline to actually send the extra.
What about investing the monthly difference instead?
The honest counter-argument: a 30-year frees up cash every month that could earn market returns. Over 15 years, invested well, that can beat the guaranteed interest savings — but market returns aren’t guaranteed and most people don’t actually invest the difference. Compare the guaranteed $257,502 saved against your realistic investing behavior, not a spreadsheet ideal.