2-1 Buydown Calculator

What a 2-1 buydown is

A 2-1 buydown is a deal attached to a mortgage: for the first year the borrower pays as if the interest rate were 2 percentage points lower, for the second year as if it were 1 point lower, and from year three the full note rate applies. The note rate itself never changes, the balance never changes, and the payoff date never moves. What changes is who chips in: a third party deposits money that covers the gap between the discounted payment and the real one.

The CFPB describes these temporary buydowns as lower payments for a limited time, usually one to three years, with the payment stepping up each year until the subsidy runs out. The 2-1 shape is the most common version. Freddie Mac research from 2023 counted funded purchase loans and found nearly two out of three temporary rate buydowns were 2-1 plans, ahead of 3-2-1, 1-0 and 1-1 variants.

That popularity has a simple cause: in a high rate market, sellers and builders need a way to soften the payment without cutting the price. A buydown does that with a smaller check than an equivalent price cut would require, and it expires on schedule.

How this 2-1 buydown calculator works

This calculator takes the deal apart before you sit at the closing table. Enter the home price and down payment, or switch the basis to a loan amount directly, then the note rate. Two selects cover the deal structure: who funds the subsidy (seller concession, builder incentive, or lender credit) and how the money is held (one lump sum in escrow at closing, or credited month by month).

The engine underneath is the standard 30 year fixed payment formula run three times on the same loan amount: once at the note rate, once at the note rate minus 2 points, and once at minus 1 point. The differences between those payments are the subsidy. On a $378,000 loan at 6.5 percent, year one bills at 4.5 percent, year two at 5.5 percent, and the escrow account covers $473.95 of month one and $242.97 of month thirteen.

Every output row maps to a line you can demand to see in the actual agreement: the year one payment, the year two payment, the full payment from month 25, the annual subsidy for each of the two years, and the total deposit. If a lender or builder quotes numbers that disagree with these, ask which rate, term or loan amount they used.

Worked example: $420,000 home with 10 percent down

Here is the default example end to end. A $420,000 home with a $42,000 down payment leaves a $378,000 loan. The note rate is 6.5 percent on a 30 year fixed term. The table shows the whole ride.

The funder deposits $8,603.06 at closing, the year one tranche being nearly twice the year two tranche because the discount is twice as deep. Two details sit inside that first number. Your first month at 4.5 percent carries 378,000 x 0.045 / 12 = 1,417.50 of interest, but the servicer still receives the full $2,389.22, because your payment plus the drawn subsidy adds up. The loan therefore amortizes on its normal schedule even while you pay the discounted figure.

Scale the same deal down and the structure holds. A $300,000 home bought with 20 percent down leaves a $240,000 loan; at a 6.25 percent note rate the payments run $1,180.66, then $1,325.29, then $1,477.72, and the total subsidy is $5,393.98. Run your own numbers in the calculator above; the ratios move with the rate, not just the loan size.

Who funds it and how the money moves

Three parties can fund a 2-1 buydown, and the source matters for how the money is handled. On an existing home, the seller usually funds it out of proceeds as a seller concession, negotiated in the purchase contract. On new construction, builders use buydowns as standing incentives because a subsidy costs less than a price cut and preserves the price comparables in the neighborhood. Lenders can fund one as a credit in some programs, though that is the least common route.

Mechanically, the money almost always lands in a separate escrow or custodial account at closing. Each month the servicer draws the difference between the discounted payment and the full note rate payment from that account, so the loan is serviced exactly as the note requires. The CFPB notes the flip side: the borrower remains obligated for the full payment regardless. If the subsidy arrangement fails or the funds run short, the discounted payment is over and the note rate payment is due.

The funding style is negotiable. A lump sum deposit at closing is standard because it protects both sides if the home sells or the loan refinances early. Month by month crediting exists, but it ties the funder to the transaction for two years, which few sellers will accept.

Qualification and program rules

Buydowns are regulated loan features, not handshake deals, and the guardrails come from the agency guides. Freddie Mac rules for temporary subsidy buydown plans cap the initial rate at 3 percentage points below the note rate, cap the plan at 3 years, and cap each yearly step at 1 point. A 2-1 plan fits inside those rails with room to spare, which is part of why it survives underwriting so smoothly.

The rule that surprises buyers most: qualification happens at the full note rate. Freddie Mac states it directly, and the CFPB framing implies it, because the borrower owes the full payment once the subsidy ends. Debt to income is computed on $2,389.22 a month in the worked example, not $1,915.27. A buyer who needs the discounted payment to qualify will not get the loan at all.

Program level restrictions also apply. Some loan types and assistance programs limit who may contribute and how much a seller can concede in total, and those concession caps interact with the buydown deposit. Ask the lender to confirm in writing that the planned funding source fits the program, because a buydown funded by the wrong party can force a redesign at the eleventh hour.

2-1 buydown vs points, price cuts and other sweeteners

Builders and sellers usually offer a menu, so the real question is which sweetener leaves you best off. The three below are not the same product wearing different hats; they work on different parts of the deal.

The trade offs run deeper than the table. Discount points cost more up front for the same monthly relief, but the saving never expires and applies to every one of the 360 payments. A price cut reduces the balance, which shrinks closing costs that scale with price and can matter at appraisal time. The buydown wins on raw monthly relief per dollar spent, which is exactly why sellers prefer it: it converts a modest check into a headline payment number on the first two years of statements.

One comparison to refuse: never measure a buydown quote against another lender quote carrying a permanently lower rate. The buydown payment is temporary by design. Compare note rates to note rates, then price the sweeteners separately.

What the subsidy costs at different loan sizes

Subsidy cost scales almost linearly with loan size, and the table below prices the same deal, a 6.5 percent note rate on a 30 year fixed term, at five loan amounts. These are the checks a seller or builder would write at closing under a lump sum structure.

Two patterns jump out. First, the subsidy runs almost exactly 2.3 percent of the loan amount at this rate, which gives both sides a quick sanity check during negotiation. Second, the rate matters as much as the size: the same $300,000 loan at a 7.5 percent note rate costs noticeably more to buy down than at 6.5 percent, because the payment gaps between the note rate and the discounted rates widen. When rates fall, buydowns get cheaper to fund; when rates rise, they get expensive fast.

When the subsidy ends and how to negotiate one

The subsidy has a hard stop, and the best time to plan for it is before closing. In the worked example the payment climbs from $2,146.24 to $2,389.22 in month 25, a step of $242.97 a month. Households that sized their budget to the year one payment feel that step twice: once in year two at $242.97, and again in year three at another $242.97. A practical habit is to bank the difference during the subsidized years, so the month 25 payment arrives pre funded.

Negotiation is where the calculator earns its keep. Ask the seller or builder for the total concession in dollars rather than accepting a labeled incentive; $9,000 of concession can fund the 2-1 structure with room left over for closing costs, or you can redirect it. Get three numbers in writing: the note rate, the bought down payments for each of the two years, and the exact deposit amount. Those three figures should match this calculator to the cent.

Finally, think about the exit. If you sell or refinance during the subsidized years, the remaining subsidy does not follow you out the door; agreements commonly leave unused funds in the account, so the funder keeps the balance. That asymmetry is another reason the 2-1 structure dominates: the funder risks only the part of the schedule the borrower uses, and buyers who plan to move within two years should weigh whether the subsidy will survive their own timeline.