Pick the year someone bought. Their principal and interest never changes for 30 years. Only property taxes and insurance move, and in Florida the homestead cap holds the tax side to 3% a year. The renter next door follows the actual national rent history over the same months.
Drag the year. Price, rent and rate fill in from history and you can overwrite any of them with a client's real numbers.
Each orange line is a household that bought in January of that year and never moved. Their payments barely move. The blue line is what a renter of a comparable home paid over the same years. Uses the tax, insurance and down payment settings above.
What to point at. The orange line is flat and the blue line is not. That is the whole argument. A renter signs up for a payment that has risen about 3.3% a year on average for 36 years and has never had a meaningful down year. A buyer with a fixed-rate loan signs up for a payment that is frozen on day one. The only pieces that move are taxes and insurance, and together they are usually a fifth to a quarter of the total, so even a sharp insurance increase moves the owner's bill far less than an ordinary rent renewal moves the renter's.
The crossover. When rates are high an owner starts out paying more per month than a renter. The chart shows that this never lasts. A buyer in 2007, about the worst timing possible, started out roughly $450 a month above rent and was still below rent by 2023, with the gap widening every year since. A buyer in 2015 started below rent on day one and now pays roughly $680 a month less. Try 2024 or 2026 with the 30-year extension turned on to show a buyer today what the next decade looks like under the same rent growth we have actually seen since 1990.
What this leaves out. Maintenance, the opportunity cost of the down payment, and the equity the owner builds. Those cut both ways and are a separate conversation. This chart answers one question only: whose monthly payment goes up.
How the numbers are built. Rent follows the CPI Rent of Primary Residence (BLS, via FRED series CUSR0000SEHA) and is scaled so that July 2026 equals $2,000 a month, roughly Zillow's national typical rent; the prefilled rent for any purchase year is that figure walked back using the index. Home prices follow the S&P CoreLogic Case-Shiller U.S. National Home Price Index (FRED CSUSHPINSA) scaled so that July 2026 equals $410,700, the Census median sales price for the second quarter of 2026. Mortgage rates are Freddie Mac's 30-year average (FRED MORTGAGE30US), averaged by month. Principal and interest assume a 30-year fixed loan. Property tax is the tax rate times an assessed value that starts at the purchase price and rises by the cap each January, never above market value. Insurance starts as a share of the purchase price and compounds at the rate you set. The projection uses the future rent growth you set, a 3% a year home value path for assessments, and your insurance growth rate. BLS did not publish October 2025 rent; it is filled in as the average of September and November. Data pulled October 15, 2026. This is an illustration, not a quote; change the inputs to match a real property.
A tool from Don Harkins Realty. Read the article it goes with: Renting in Retirement: Who Really Pays for the Roof?