Temporary Mortgage Buydown Calculator

Understand the home-finance decision

What the Temporary Mortgage Buydown Calculator is for

Calculate first- and second-year borrower payments and the subsidy required before the note-rate payment begins.

It keeps the property value, balance, cash amounts, rate convention, payment timing, and comparison horizon visible so the result can be checked against an actual quote, statement, budget, or contract.

Calculation structure

Follow the money through time

Subsidy = 12 × (note-rate payment − year-one reduced-rate payment) + 12 × (note-rate payment − year-two reduced-rate payment).

Visual explanation

See which inputs change the result

Stage 1→Stage 2→Later stageRecalculate from the balance remaining at each changeSubsidy = 12 × (note-rate payment − year-one reduced-rate payment) + 12 × (note-rate payment − year-two reduced-rate payment).

Read the estimate correctly

Use the result with its assumptions

Model a 2-point first-year and 1-point second-year reduction from a 6% note rate.

The note rate and its full payment remain contractual. This is a cash-flow schedule, not product eligibility or disclosure advice.

Quick guide

How to use this calculator

Enter the figures from your mortgage offer, statement, contract, property budget, or scenario.
Keep currencies, rate conventions, periods, and balances consistent; compare multiple plausible scenarios where future rates or costs are uncertain.
Use the component outputs to verify the result and review the calculator-specific boundary before acting.

Calculation method

Subsidy = 12 × (note-rate payment − year-one reduced-rate payment) + 12 × (note-rate payment − year-two reduced-rate payment).

Mortgage schedules use stable level-payment arithmetic and advance only the explicitly entered scenario. Results are checked for finite, principal-reducing behavior and round only for display.

Worked example

Practical example

Model a 2-point first-year and 1-point second-year reduction from a 6% note rate.

Subsidy = 12 × (note-rate payment − year-one reduced-rate payment) + 12 × (note-rate payment − year-two reduced-rate payment).

Supported inputs

Precision and limits

Visible input limits

Amounts are capped at 1e12, rates at 1000% unless a narrower percentage applies, and schedules at 1,200 months unless a frequency comparison explicitly documents more payment periods.

International scope

No currency, country, tax system, mortgage program, lender threshold, insurance rule, market rate, escrow law, or contract term is assumed.

Decision boundary

These are arithmetic scenarios, not offers, approvals, regulated disclosures, forecasts, valuations, legal interpretations, hardship advice, or recommendations.

Calculator-specific assumptions

The note rate and its full payment remain contractual. This is a cash-flow schedule, not product eligibility or disclosure advice.