The rent vs buy 5% rule is the simplest math I’ve found for answering one of the most stressful questions in personal finance: am I throwing money away by renting?
I’ve rented in New York, New Jersey, DC, and now Philadelphia. I know what it feels like to hand over $1,800 a month and wonder if I’m just making someone else rich. And I know how complicated the rent vs buy decision feels when you factor in down payments, interest rates, maintenance costs, and everything else.
But this one calculation cuts through all of it.
What Is the 5% Rule for Renting vs Buying?
The rent vs buy 5% rule gives you a monthly dollar figure that tells you whether renting or buying makes more financial sense at a given home price.
The formula:
(Home price × 0.05) ÷ 12 = Your rent vs buy breakeven number
Example:
You’re looking at a $300,000 home in Philadelphia.
$300,000 × 0.05 = $15,000 $15,000 ÷ 12 = $1,250/month
If you’re currently paying more than $1,250/month in rent — buying that $300,000 home is likely the better financial move.
If you’re paying less than $1,250/month — renting might still make more sense, depending on your situation.
That’s it. One number. Immediate clarity.
Why Rent Keeps Going Up (And It’s Not Just Greed)
Before we get into when buying makes sense, it’s worth understanding why rent has become so brutal — because the reasons go deeper than most people realize.
Property taxes and insurance have exploded.
Over the last five to six years, property taxes and landlord insurance premiums have increased dramatically in most markets. Landlords don’t absorb those costs — they pass them directly to tenants through higher rent. When a landlord’s insurance bill jumps $3,000 a year, that $250/month has to come from somewhere.
Airbnb pulled rental supply off the market.
Every home that became a short-term rental is one fewer home available for long-term renters. In cities and suburbs with high tourism or travel demand, Airbnb has meaningfully reduced the supply of available rental units — which pushes prices up for everyone else.
AI is optimizing rent in real time.
Large property management companies now use algorithmic pricing tools that analyze occupancy data, local demand signals, and competitor pricing to set and adjust rents dynamically. The same way airlines price seats, some landlords now price apartments. The algorithm doesn’t care that you’ve been a good tenant for three years.
Remote work increased demand for space.
When people started working from home full time, a one-bedroom became harder to live in. Demand for larger units — two bedrooms, home offices, extra square footage — jumped. More demand, same supply, higher prices.
None of this is going away. Which is exactly why the rent vs buy calculation deserves serious attention.
The Rent vs Buy 5% Rule Applied to Philadelphia
Let me run the rent vs buy 5% rule across a few real Philadelphia price points so you can see how it plays out.
$200,000 home:
$200,000 × 0.05 ÷ 12 = $833/month If you’re paying more than $833 in rent → buying likely makes more sense
$300,000 home:
$300,000 × 0.05 ÷ 12 = $1,250/month If you’re paying more than $1,250 in rent → buying likely makes more sense
$400,000 home:
$400,000 × 0.05 ÷ 12 = $1,667/month If you’re paying more than $1,667 in rent → buying likely makes more sense
$500,000 home:
$500,000 × 0.05 ÷ 12 = $2,083/month If you’re paying more than $2,083 in rent → buying likely makes more sense
In Philadelphia, the median one-bedroom rent is somewhere in the $1,400–$1,800 range depending on the neighborhood. Which means for a significant portion of Philadelphia renters, the 5% rule suggests buying is the better financial move — if they can qualify for financing.
What the 5% Rule Is Actually Measuring
The 5% figure isn’t arbitrary. It’s a rough estimate of the total unrecoverable annual cost of owning a home, expressed as a percentage of the home’s value:
- ~3% for the opportunity cost of your down payment (what that capital could earn invested elsewhere)
- ~1% for property taxes (rough average — varies significantly by location)
- ~1% for maintenance and repairs (the money you spend keeping the home livable)
These are the costs of ownership that you never get back — the equivalent of rent in the ownership equation. Mortgage principal payments don’t count because you’re building equity. Interest costs are partially offset by the mortgage interest deduction for some buyers.
The 5% rule essentially asks: is my rent higher or lower than what it would cost me just to own this home, excluding the equity-building component?
What the 5% Rule Doesn’t Account For
The rent vs buy 5% rule is a starting point, not a final answer. Here’s what it doesn’t capture:
Appreciation. If you buy in a neighborhood where values are rising, your equity grows beyond what your mortgage paydown generates. The 5% rule ignores this upside.
Flexibility. Renting gives you the ability to move without the friction of selling. If your job situation is uncertain or you might relocate, renting has real non-financial value.
Transaction costs. Buying and selling a home costs roughly 8–10% of the home’s value in total (agent commissions, closing costs, transfer taxes). If you’re not planning to stay for at least 3–5 years, those transaction costs can wipe out any financial advantage from buying.
Financing costs. The 5% rule doesn’t factor in your specific interest rate. At 7% on a 30-year mortgage, your monthly payment is significantly higher than at 5%. The rule gives you a directional answer — your actual mortgage payment tells you the real number.
My Honest Take
I’ve been renting my entire adult life in the U.S. And I’ll be honest — every time I’ve run the rent vs buy 5% rule against what I was actually paying in rent, buying came out ahead on paper.
The barrier has always been the down payment and the qualifying income — not the monthly cost comparison.
Which is why I spend so much time on this blog studying the programs that actually lower those barriers: USDA loans, FHA financing, down payment assistance, house hacking. Because the math of renting vs buying often points toward buying — it’s the upfront friction that keeps people in rentals longer than the numbers suggest they should be.
If you want to run your own numbers, the calculator below does the full comparison — monthly costs, break-even timeline, and equity building over time.
Not financial advice — just someone doing a lot of research and asking a lot of questions.