The Break-Even Horizon

Alex Rivera, Wealth Architect at The Wealth Grid

Deep Dive | August 28, 2026 | The Wealth Grid

The thirty year fixed averaged 6.67 percent in Freddie Mac's most recent weekly survey. Home sales are running about 6.1 percent above last year, inventory has loosened, and the rent versus buy argument has gotten loud again.

Both sides are using bad math.

The buy side compares a mortgage payment to a rent check and calls the difference wealth building. The rent side compares the same two numbers and calls the difference savings. Both are answering a question that does not determine the outcome.

Today we build the real calculation. It is not difficult, but it has four inputs that nearly every online calculator either omits or fakes, and those four are where the entire answer lives.

Fair warning on where this ends up. The mortgage rate matters much less than you have been told, and one number nobody estimates matters much more.

Start here, because the framing is what causes the errors downstream.

Renting and owning are not two ways to pay for shelter. They are two different transactions that happen to produce the same roof.

Renting is a pure consumption purchase. You pay for a month of housing, you consume a month of housing, and the transaction closes. There is nothing left over on either side. It is clean, and its cleanliness is the product.

Buying is a leveraged purchase of an illiquid asset, bundled with a consumption purchase, with a large fixed cost charged at both ends of the holding period.

Once you see it that way, the right question stops being which monthly number is lower. It becomes the same question you would ask about any leveraged asset with a heavy load: how long do I have to hold this before the return clears the cost of getting in and out.

That is the break even horizon. Everything else is an input to it.

One. The round trip.

This is the largest omission and the most consequential.

Getting in costs roughly two to three percent of the purchase price. Origination, appraisal, title, inspection, recording, prepaid escrow. Getting out costs considerably more: five to six percent in commission even in the softer commission environment that followed the settlement changes, plus title, transfer taxes, and the concessions buyers now routinely ask for.

Call the round trip nine to ten percent of the value of the asset.

On a 500,000 dollar house that is roughly 50,000 dollars that has to be earned back before you have broken even on the transaction alone. Not before you have profited. Before you are level.

At three percent annual appreciation, clearing 50,000 dollars takes a bit over three years, and that is three years of appreciation doing nothing except paying the friction.

Two. Maintenance and capital expenditure.

Calculators either leave this out or plug in a token figure. The honest range is one to two percent of the home's value annually, averaged over a long holding period. Call it 1.25 percent as a working number.

On 500,000 dollars that is 6,250 dollars a year, or about 521 dollars a month. It does not arrive monthly. It arrives as nothing for four years and then a roof.

This is the cost renters genuinely do not pay, and the one owners genuinely forget. Every landlord in the country prices it into rent. Every prospective buyer assumes they are the exception.

Three. Opportunity cost, on both pieces.

Two separate pools here and people usually count neither.

The down payment is capital that stops being invested. One hundred thousand dollars that would otherwise be compounding is now sitting in drywall. At a modest six percent that is 6,000 dollars of forgone return in year one, growing from there.

Then there is the monthly differential. If owning costs more per month than renting, that gap is money the renter can invest. If owning costs less, the reverse. Either way it compounds, and over a seven year comparison it is not a rounding error.

Four. The amortization schedule.

People treat the whole mortgage payment as forced savings. It is not, and early on it is barely savings at all.

On a 400,000 dollar loan at 6.67 percent, the payment is about 2,573 dollars a month. In the first year you will pay roughly 30,900 dollars and about 26,600 of that is interest. Principal reduction is somewhere near 4,300 dollars.

So of that 2,573 dollar payment, about 360 dollars a month is actually going to you in year one. The rest is the cost of borrowing, which is the owner's version of rent. It is paid to a bank instead of a landlord and it is gone just the same.

That ratio improves every year. But it improves slowly, and in the years when the break even question is live, it is nowhere near where people assume.

Put it together on a 500,000 dollar house with twenty percent down, against an equivalent rental at 2,800 dollars a month.

Owning, monthly. Principal and interest 2,573 dollars. Property tax at 1.1 percent, 458 dollars. Insurance, 150 dollars. Maintenance reserve, 521 dollars. Total carrying cost about 3,702 dollars.

Of that, roughly 360 dollars is principal in year one. So the true monthly cost of owning, meaning money that leaves and does not come back, is about 3,342 dollars.

Renting, monthly. 2,800 dollars, all of it consumed, plus renters insurance that rounds to nothing.

The renter is out of pocket about 542 dollars a month less, and has 100,000 dollars invested that the owner does not.

Now the owner's side of the ledger. Appreciation at three percent on 500,000 dollars is 15,000 dollars in year one, and it compounds on the whole asset rather than on the equity, which is the leverage working. Principal reduction adds about 4,300 dollars. Against that, 50,000 dollars of round trip cost sits waiting to be paid.

Grind that forward and the crossover on these assumptions lands somewhere around year five to seven. Before that the renter is ahead. After that the owner pulls away, and keeps pulling away, because appreciation compounds on a leveraged base and rent keeps rising while a fixed payment does not.

I want to be careful here. Those are illustrative numbers and yours will differ, sometimes enormously. Property tax in Texas or New Jersey rewrites the whole thing. So does an appreciation assumption of one percent instead of three.

Which is the actual lesson. This calculation is not universal. It is local, and it is personal, and anyone giving you a general answer is selling something.

Before building a full model, run the cheap filter first.

Take the purchase price and divide it by the annual rent on a comparable property. That is the price to rent ratio, and it sorts markets faster than anything else you can do in thirty seconds.

Under 15, buying is usually favored and the break even arrives quickly. Over 21, renting is usually favored and it can stay favored for a decade. Between 15 and 21 the answer genuinely depends on the four costs above and on your own horizon.

Our example house at 500,000 dollars against 33,600 dollars of annual rent gives a ratio of about 14.9. That is why the crossover showed up in year five or six rather than year twelve.

Run the same house in a metro where 500,000 dollars rents for 1,900 dollars a month and the ratio is 21.9. Same rate, same buyer, same costs, and buying does not break even for a very long time.

The rate did not change. The market did.

Here is where I want to land, because it is the thing almost nobody estimates and it dominates every other input.

The decisive variable is not the mortgage rate. It is the probability that you are still in that house in year seven.

Everything above establishes that ownership needs roughly five to seven years to clear its own friction under ordinary assumptions. So the question that determines the answer is whether you will actually be there.

And people are terrible at this. Not slightly. Systematically.

Ask a buyer how long they plan to stay and you will hear forever, or at least ten years. Then look at what happens. Jobs relocate. Relationships change in both directions. Kids arrive or leave. Parents get sick. A better opportunity appears in another city. The median owner does not make it anywhere near the horizon they projected on the day they signed.

So do the thing that feels uncomfortable and estimate honestly. Not what you hope. What you would bet on.

If your realistic probability of still being there in seven years is above roughly seventy percent, the math generally favors buying in a normal price to rent market. Below fifty percent, renting is usually correct even if the monthly payment looks attractive, and a low rate does not rescue it, because a low rate reduces the carrying cost and does nothing at all about the ten percent round trip.

That is the part people get backwards. Rates change the monthly number, which is the part you feel. Horizon changes whether the transaction was a good idea, which is the part that shows up in your net worth.

The tax benefit is smaller than it used to be. Mortgage interest is only deductible if you itemize, and since the standard deduction went up, most households do not. Run your actual numbers rather than assuming a deduction that a large majority of owners no longer receive. The state and local cap limits it further in high tax states, which are exactly the states where the deduction would have mattered most.

Do not treat the house as your portfolio. A primary residence is a consumption asset with an investment attached, and the investment is undiversified, illiquid, leveraged, geographically concentrated, and correlated with your local job market, which is often correlated with your income. That is a genuinely risky asset by every measure we would apply to anything else. It is fine to own one. It is not fine to count it as your diversification.

Two things make this practical rather than theoretical.

First, get the real costs out of the documents. Loan estimates and closing disclosures are designed to be comparable and are somehow still unreadable. I paste them into Galaxy.ai and ask for one thing: total cash to close and total cost of credit over the first seven years, with every fee itemized. It takes a minute and it has caught a junk fee more than once.

Second, if you already own, start tracking maintenance for real. Almost nobody knows their actual number, which means almost nobody can run this calculation on their own house. I have Make.com catching anything I tag as house spend and dropping it into a running annual total. Three years of that and you stop guessing at 1.25 percent and start using your own figure.

I built the full break even model as a working spreadsheet. It runs both sides year by year for fifteen years, with all four missing costs included, the amortization schedule broken out so you can see the principal share climb, the opportunity cost on both the down payment and the monthly differential, a price to rent screen, and a sensitivity table so you can see how the crossover year moves when appreciation, tax rate, or maintenance changes.

It also has the horizon probability worksheet, which is the uncomfortable one and the one that matters.

Reply with the word HORIZON and I will send you The Break-Even Model, free. Reply HORIZON and it comes straight to you.

The Grid Inner Circle is where this kind of thing gets genuinely useful, because a model is only as good as the inputs and the inputs are local. Members are running their own metros through this and posting what they find, which is how you learn that the answer in Raleigh and the answer in Seattle are not remotely the same question.

Twenty nine dollars a month. Or 499 dollars once for founding lifetime access, locked at that number permanently regardless of where the monthly goes.

Reply GRID and I will send you the details.

There is no general answer to rent versus buy, and the confidence with which people deliver one should tell you how carefully they have looked.

What there is instead is a structure. Ownership carries a round trip cost near ten percent of the asset. That cost has to be cleared by appreciation, amortization, and the carrying differential before you are level. Clearing it takes years, not months. And whether you get those years is a question about your life, not about the bond market.

Run the model on your actual house, in your actual market, with your honest horizon.

Then buy the thing or rent the thing and stop reading arguments about it.

Sunday is The Edge, and I want to pull on something that ran underneath all three pieces this week without any of them naming it.

Alex Rivera, Wealth Architect at The Wealth Grid

Wealth is a system, not a guess.