Putting more cash down lowers your mortgage. Investing that cash instead could grow it faster. Compare both strategies to see which builds more net worth over your timeline.
Say you have enough cash to put 50% down on an $800,000 home. Option A puts all of it toward the down payment, leaving a smaller loan and less mortgage interest paid over time. Option B puts down less, say 20%, and invests the freed-up cash in the market instead. Every slider on this page has a matching number field: drag to explore, or type exact figures if you already know your numbers. This calculator tracks both paths and adds up home equity plus invested cash at the end of your timeline to see which strategy leaves you further ahead.
Every dollar you put toward a down payment is a dollar that stops earning a market return and instead earns a guaranteed return equal to your mortgage rate, since it's interest you no longer have to pay. Paying down more of your mortgage is effectively a risk-free investment at your mortgage rate. Investing that cash instead is a bet that market returns will outpace that rate over your time horizon. This is the same opportunity-cost logic tested on the CFP exam and in the finance sections of real estate licensing exams.
This is the full principal and interest you'll pay on Loan B if you carry it to the end of its term, added up into a single dollar figure. It's a fixed number based only on your loan amount, rate, and term, unrelated to how your investment actually performs. The idea is simple: that's the real dollar cost of borrowing more instead of putting more down, so it's the number your invested cash needs to grow past for taking on the bigger loan to have been worth it. Compare it directly against the "Invested Cash, Grown" figure below.
Option A's smaller (or zero) mortgage payment is assumed to come from income, same as always. Option B's investment account is charged its extra monthly payment (the amount above what Option A pays) every month, alongside its growth, so the comparison reflects the true cost of carrying a bigger loan. This tool still doesn't model taxes, private mortgage insurance, or the psychological value of owning more of your home outright, and investment returns are never guaranteed, unlike the effectively fixed cost of your mortgage rate. Use this as a framework for the tradeoff, not a guarantee of results. For the mortgage side alone, see our Mortgage Calculator, and for the classic renting-vs-owning decision, see our Rent vs. Buy Calculator.
Comparing a guaranteed return against an expected return, and reasoning about leverage and opportunity cost, are recurring themes on the CFP exam, Series 65, and CFA Level 1. If you're pursuing a real estate license, mortgage structuring and loan-to-value concepts appear on our General Real Estate practice exam and the state-specific versions for California, New York, New Jersey, and Pennsylvania.
Yes. Paying down more of your mortgage is a guaranteed return equal to your mortgage rate, with no market risk. Investing the difference could outperform that, but it could also underperform it, especially over shorter timeframes where markets are more volatile.
No. Mortgage interest deductibility depends on whether you itemize and current tax law, so it isn't included here. If it applies to you, the effective cost of carrying a larger loan is somewhat lower than the stated mortgage rate.
That depends on your portfolio and risk tolerance. A diversified stock portfolio has historically returned somewhere in the 7-10% range annually over long periods, before inflation, though any given year or decade can vary significantly. Use a conservative assumption if you want a cautious read on the comparison.
Because investing more means putting down less, which means borrowing more on Loan B. A bigger loan carries a proportionally bigger total repayment cost, so this figure rises and falls directly with your investment amount. Since the loan's total cost and your investment amount move together, the target is always calibrated to the specific scenario you've set up.
Because the total repayment is the real cash outlay of carrying the loan, not just its cost. Most of that repayment is your own principal coming back to you as home equity rather than a true expense, so comparing your investment against the full repayment figure, not just the interest portion, gives you the complete picture of what borrowing more actually costs versus what you get back.
Yes. Each slider has a paired number input. Type directly into any gold field to enter a precise figure, and the slider along with all results update immediately.
Opportunity cost and mortgage math like this show up directly on CFP and real estate licensing exams. Practice for free.
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