Model buying a house or car

When you want to see what a home or vehicle purchase would do to your money, the What-if planner has two templates for it: Buy a home and Buy a car. Each one fills in a purchase — an asset for what you're buying, an amortized loan for what you'd borrow, and a monthly payment bill — as part of that change, along with a cash line that takes the down payment out of an account you choose, so your net worth change is accurate. A car can also be leased.

An amortized loan is one you pay off in equal monthly payments over a set number of months, with each payment covering part interest and part principal.

Before you start

• Buy a home and Buy a car live inside the What-if planner, which is free for the account owner and their spouse.
• Start the purchase from a scenario — either as a new scenario's first change, or stacked onto one you already have. See Test a what-if scenario.

Steps

1. In the What-if planner, click the dashed Add New Scenario card, or open an existing scenario and click + Add a change at the bottom of the page.
2. Under What's your scenario? (or What else is changing?), pick Buy a home or Buy a car. It fills in a $350,000 home with $35,000 down, or a $30,000 car with $5,000 down. It also fills in your other matched items and adds starting costs, like property taxes and home insurance for a home, or car insurance for a car. Extras such as HOA dues show under Also add? (see Test a what-if scenario for the full list).
3. If you're creating a new scenario, name it and click Create Scenario; if you're stacking it onto one already open, click Add change. The purchase opens as its own section.
4. In that section's Adding list, change the Price and Down payment to your numbers. Both save as you type (on blur or Enter). For a car, you can also switch between Buy and Lease, pick New or Used, and change Taxes & fees.
5. Click More options on the purchase to set the rest: a Name (for example, "FL House" or "New Truck"). For a home, set Closing Costs (lender, title, and other fees paid in cash at closing; it starts at $10,000, and blank skips it) and Mortgage insurance (PMI), a year (it starts at 0.7% of the loan and applies while the down payment is under 20%). For a car, you can also add taxes and fees to the loan and change the value lost when you buy it.
6. If you entered a down payment or closing costs, choose Pay down payment from (or Pay down payment and closing costs from, once closing costs are entered) — a cash account, an item you added to this scenario (like sale proceeds), or Money not tracked here for something like a gift. It starts on the account holding the most cash. If that isn't enough, see When one account isn't enough.
7. Set the Interest Rate. It starts at 6.5% for a home and 7.0% for a vehicle — change it to your rate.
8. Set the term — Term (years) for a home (starts at 30) or Term (months) for a vehicle (starts at 60).
9. Check the This will add to your scenario preview — it shows the asset, the loan, the estimated monthly payment, and the cash coming from your chosen source. Click Save Changes.

What the purchase creates

For a home named "FL House" with a down payment paid from an account, the purchase adds:

• Asset — FL House: its value equals the purchase price.
• Debt — FL House Mortgage: the loan amount, which is the purchase price minus the down payment.
• Bill — FL House Payment: the amortized monthly payment, set to Monthly and marked as a need.
• Bill — FL House PMI: monthly mortgage insurance, added only while the down payment is under 20% and PMI is above 0%.
• Asset — FL House Down Payment (or FL House Cash to Close when you entered closing costs): a negative amount equal to the down payment plus closing costs, subtracted from the account you chose. This is what keeps the purchase from overstating your net worth — the cash moving into the home is no longer double-counted as still sitting in your account. Money marked Money not tracked here or borrowed isn't subtracted.
• Debt and Bill for any money you borrow for the down payment (for example FL House Personal Loan and FL House Personal Loan Payment), using the same payment formula as the mortgage.

A car purchase works the same way, except the debt is named "… Loan" instead of "… Mortgage", the car's value starts lower by the value lost when you buy it (about 10% for a new car), the cash line is named Down Payment & Fees, and there's no PMI. A leased car adds only a … Lease bill and the cash due at signing. The monthly payment comes from a standard amortized-loan formula using your price, down payment, interest rate, and term. You can check the same math with the Loan Payment Calculator.

At 0% down, there's no cash line to subtract. At 100% down, there's no loan and no monthly payment bill — just the home and the cash line. A down payment can't be more than the purchase price.

When one account isn't enough

If the account you picked can't cover the down payment (and closing costs), the window says You're $X short. and offers three fixes:

• Add another account — adds your next-biggest cash account. Amounts fill in on their own, biggest balance first, until it's covered. You can change any amount.
• Borrow the rest — adds a loan for the gap. Pick the kind: 401(k) loan, Personal loan, Family loan, Home equity line, or Other loan. Each starts with a typical rate and length (for example 12% over 60 months for a personal loan, 0% for a family loan) — change them to your real terms. The loan and its monthly payment are added to the scenario.
• Money not tracked here — for a gift or money the app doesn't track. It takes whatever is left and nothing is subtracted.

Once more than one source is used, each shows an amount and the window says Covered or how much is still to cover. Remove an account or loan with its X. With one account that has enough, it stays a single choice with no amounts.

Good to know

• The items stay grouped, inside the purchase's own section. Change the price, down payment, or anything under More options and all its linked items are rebuilt. Remove the change and they all go away together — you can't edit or delete the asset, loan, payment, or cash line on their own.
• Only two templates build a purchase. Buy a home and Buy a car are the only templates that create a linked asset, loan, and payment for you. For anything else, add items individually with Add Item in the Something else section.
• A scenario can only hold one housing purchase or move at a time. Buy a home shares its slot with Moving and Downsize — you can't stack two. Buy a car has no such limit, so you can stack more than one car purchase (or a car purchase alongside other changes) as long as they don't touch the same real item.
• Purchases made before stacking existed still work. A bundle added to a scenario created before this layout shows in the Something else section with its own edit (pencil) and remove (X) controls, the same as any other hand-added item.
• Trade-ins. In a Buy a car change, a car you own has a Trade in choice. Its value goes toward the new car, and anything still owed on it is added to the new loan.
• Short on cash shows one line. If your choices don't cover it, you'll see "You're $X short." with buttons to fix it (see above). Until it's covered, the whole amount still comes out of your cash, so net worth is never overstated.
• Sale proceeds can pay for it. If a stacked Sell a car or a Moving change sells something, or you add an asset by hand for money from selling something, it shows up as a choice in Pay down payment from too.
• It's still point-in-time. Like the rest of the What-if planner, a purchase compares your money today against today with it applied. It doesn't project the loan's payoff over the years — the retirement projection handles long-term loan payoff instead.
• Beth or a connected AI assistant can build a purchase too, filling in the price, down payment, rate, term, closing costs, and which accounts pay, with What-if planner Update access. See What Beth can do.