Move-Up Calculator: What It Costs to Trade Up

You own a house, you have equity, and you want more room — but the loan you would be giving up is cheaper than anything on offer today. Enter when you bought and what you still owe, and this works out what your sale actually nets after commission and costs, what the new payment becomes at today's rate, and how much house you could buy without the payment running away from you.

Moving up costs you, every month+$2,205/moYour payment goes from $1,510 at 2.96% to $3,715 at 6.50% — principal and interest only. The $279,215 your sale nets covers 31% of the new house, leaving a $587,785 loan.

The home you own now

Your Rate

Amount You Still Owe

Monthly Payment (P&I)

/mo

Worth Today

Time left on this loan

24 yr 11 mo

Paid off

Sep 2051

Interest still to pay

$131,604

Equity on paper

$317,360

Enter principal and interest only: escrowed tax and insurance are not paying the loan down, so including them makes the time left look years shorter than it is.

That is $317,360 of equity on paper. How much of it survives the sale is the next panel.

Selling it

Agent Commission

Closing Costs on the Sale

The sale price is the $635,745 you entered as what the house is worth today. If you expect to take less than that, put the figure you expect to get in Worth Today and everything here follows from it.

Commission is negotiable and has been more openly so since the 2024 NAR settlement; the 5% starting figure is a midpoint, not a rule.

Closing costs are estimated at 1% of the sale price — title, escrow, transfer tax, attorney and recording fees. This one varies more by state than any other number on the page (transfer tax alone runs well above it in parts of the north-east and the Pacific north-west), so replace it with your title company's figure once you have one. Clear the field to come back to the estimate.

Selling for $635,745 costs $38,145 in commission and fees, and $318,385 goes straight back to your lender.

What can you actually buy?

Working the same numbers backwards: with $279,215 in hand and a 6.50%, 30-year loan, here is the most house each monthly payment buys.

If your payment is	Monthly	Change	Loan	Max price
Exactly what you pay now	$1,510	+$0	$238,898	$507,955
25% more	$1,888	+$378	$298,623	$566,508
50% more	$2,265	+$755	$358,348	$625,062
100% more	$3,020	+$1,510	$477,797	$742,169

Worth sitting with: holding your payment exactly where it is today caps you at $507,955 — about $127,790 less than the house you already own. At 2.96% your current payment buys far more house than the same money buys at 6.50%. Moving up in square footage means moving up in payment; there is no version of this where the payment stays flat and the house gets bigger.

Why moving up costs more than the price difference

The sticker price gap between your house and the next one is the number everybody anchors on, and it is the least important one on this page. Three other things move at the same time. Your rate resets to whatever the market is charging today, and for anyone who borrowed in 2020 or 2021 that is a doubling. Your balance goes up, because the proceeds rarely cover as large a share of a bigger house as your original down payment covered of a smaller one. And the clock restarts: a fresh thirty-year loan undoes every year of amortization you have already paid for, which is why the lifetime interest difference on this page is so much larger than the price difference between the two houses.

Where to go from here

This page compares loan against loan. For the whole payment on the house you are moving to — property tax, insurance, PMI and HOA on top of what is shown here — run the price through the mortgage calculator. If the new rate is the part you cannot stomach, the prepayment calculator shows what throwing extra at the balance actually buys you, and the refinance calculator is where to model swapping the new loan for a cheaper one later, if rates come back down.

What this page assumes

Figures are estimates for planning, not a loan offer. Only principal and interest are compared, so the real gap is wider than what is shown: the more expensive house also carries more property tax and more insurance, and if your proceeds do not reach 20% down you will pay PMI on top. Beyond that: both rates are fixed for the full term, so ARMs, buydowns, and points are not modeled; agent commission is negotiable; the calculation assumes the sale funds the purchase cleanly, with no bridge loan, rent-back, or double move; and moving costs, repairs, and buyer concessions are not included. Confirm anything consequential with your lender and your agent.

Sale price	$635,745
Agent commission	−$31,787
Closing costs on the sale	−$6,357
Mortgage payoff	−$318,385
Net proceeds	$279,215
Closing costs on the purchase	−$17,000
Extra cash from savings	$0
Down payment	$262,215

Payment now (2.96%)	$1,510
Payment after (6.50%)	$3,715
Monthly difference	+$2,205
Interest left if you stay	$131,604
Interest on the new loan	$749,687
Lifetime difference	+$618,083