How to Use the Rent vs. Buy Calculator
Enter the home price, your expected down payment and mortgage rate, the comparable rent, and your planned time horizon — then check the appreciation rate and investment return assumptions, since these two inputs affect the result more than almost anything else and are worth adjusting to your actual expectations rather than leaving at default.
The Rent vs. Buy Calculator projects both paths to the same future point in time — here's what to focus on to get a comparison that reflects your actual situation.
The inputs worth double-checking
Home price, down payment, mortgage rate, and comparable rent are the straightforward inputs. The two that most change the outcome — and are easiest to leave on a generic default — are the assumed home appreciation rate and the assumed investment return on the renting side. Adjusting both to match your actual local market and investment approach gives a far more personally meaningful result.
Setting a realistic time horizon
The result can shift meaningfully between a 5-year and a 15-year horizon, so it's worth running more than one horizon if you're genuinely unsure how long you'll stay — treating the output as a single fixed answer, rather than a range across plausible horizons, can be misleading if your actual plans are still flexible.