PlainFigure

Mortgage buydown calculator

Estimate 2-1, 1-0, and custom temporary buydown payments, subsidy cost, seller credit shortfall, payment jump, and whether permanent points may be a cleaner use of credit.

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Estimate the buydown path

Temporary buydown math estimates principal and interest only. Taxes, insurance, HOA dues, PMI, and escrow changes are excluded.

Note-rate P&I
Total subsidy required
Credit surplus / shortfall
Payment jump
Year 1 payment
Year 1 savings
Year 2 payment
Year 2 savings
Holding-period savings
Points comparison
Points break-even
Unused credit use
PeriodRate used for paymentMonthly P&IMonthly savingsMonthsSubsidy needed

The subsidy estimate equals the monthly difference between the note-rate payment and the temporary reduced-rate payment for the buydown months.

Methodology notes

Payment math

Each payment uses the standard fixed-rate amortization formula with the original loan amount and term. Temporary rates affect the borrower payment, not the note rate.

Subsidy account

The estimated subsidy is the sum of note-payment minus reduced-payment differences over year one and, when applicable, year two.

Credit tradeoff

Available credit is compared with the subsidy. Any surplus may be more useful for closing costs or permanent points, subject to lender and program limits.

Results are estimates for educational purposes only and are not financial advice. Confirm buydown eligibility, credit caps, qualification rules, and unused subsidy handling with your lender. See full disclosure.

Mortgage buydown FAQ

What does 2-1 mean?

A 2-1 buydown commonly lowers the first-year payment as if the rate were two percentage points lower, then one point lower in year two, before returning to the note-rate payment.

Is the subsidy a discount?

Usually no. It is an upfront fund that covers the scheduled payment difference. The note-rate loan still amortizes under the lender's buydown agreement.

What if I sell early?

Unused subsidy treatment depends on the agreement. Some structures credit it to principal or payoff; others follow lender-specific rules.

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