I ran this comparison in the calculator last Diwali week for three friends — two took 30 years at ~6% ($1,439 on $240,000) for cash-flow room with kids and single incomes, one took 15 years (~$2,025) on dual income with an 8-month buffer. Here is how to decide for your numbers.
Part of the mortgage calculator guide. Compare your scenarios in the mortgage calculator (try both tenures) and structure options in the loan calculator.
For informational purposes only — not financial advice. Estimates may vary; consult a qualified financial advisor for decisions. See /terms.
The numbers: $240,000 at illustrative rates
| Term | Monthly P&I | Lifetime interest | Equity at year 5 |
|---|---|---|---|
| 30 years @ 6% | $1,439 | ~$278,000 | ~$17,000 |
| 15 years @ 6% | ~$2,025 | ~$125,000 | ~$68,000 |
Shorter terms usually price ~0.5% lower, widening the gap further — table holds rates equal to isolate tenure. The 15-year costs ~$586 more monthly ($2,025 vs $1,439) but ~$150,000 less in lifetime interest (~$125k vs ~$278k). Faster equity also drops PMI years sooner on low-down-payment loans. Pick your pain — then automate for it.
Rates and examples as of Sept 2026, illustrative only — not a lender offer. Excludes taxes, insurance, PMI, HOA, fees and ARM resets.
When the 15-year wins (checklist)
- Payment under 28% of gross income with 6-month emergency fund intact after down payment and closing (2–6% of price).
- Stable dual or high income — job loss must not turn the bigger payment into distress within months.
- Staying 10+ years — interest savings compound with time; movers at year 4 capture little of the gap.
- Maxed tax-advantaged savings already — extra dollars beat mortgage interest only after retirement accounts are fed (consult your advisor).
The hybrid most people should consider
Take the 30-year, overpay the 15-year difference voluntarily (+~$586/month on this example). Same destination when times are good, with a built-in escape hatch when they are not — skip overpayments in lean months with zero penalty. Extra-payment math in overpayment guide; what amortization does year by year in amortization guide.
The forgotten 20-year middle path
Between the two famous terms sits the 20-year: payments ~15% above 30-year (vs ~40% for 15-year) with roughly two-thirds of the interest savings. For buyers who fail the 15-year checklist on payment size but hate 30-year interest totals, it is the compromise lenders rarely advertise — ask explicitly, since many quote only 15/30 menus. On $240,000 at 6%: ~$1,719/month, ~$173,000 lifetime interest — splitting the gap almost evenly. Pair with modest overpayments and you land near 15-year totals with 20-year flexibility. Model all three tenures in the calculator before letting a lender frame the choice as binary.
Three traps (both directions)
- 15-year house-poor: payment fits at 33% DTI, then the roof, car and daycare arrive. The interest saved means nothing in foreclosure.
- 30-year drift: lower payment breeds lifestyle inflation; the “I'll overpay” plan dies without autopay. Automate the extra principal or admit the 15-year was right.
- Refinance blindness: starting 30-year at 7% and never revisiting when rates fall to 6% wastes the option value — break-even math in refinance guide.
For informational purposes only — not financial advice. Estimates may vary; consult a qualified financial advisor for decisions. See /terms.