Down Payment Calculator🇺🇸

How a down payment affects your mortgage

The down payment is the portion of the purchase price you pay upfront. The rest becomes your loan principal. A larger down payment means a smaller loan, which lowers your monthly payment and reduces the total interest you pay over the life of the mortgage.

For US conventional mortgages, putting down at least 20% also eliminates the need for private mortgage insurance (PMI), which lenders typically require on loans with less than 20% equity. PMI protects the lender, not the buyer, and adds a recurring cost until you reach 20% equity.

A bigger down payment can also change the quality of the application even before you look at the mortgage payment. Lower loan-to-value ratios may make a file look less risky to a lender, reduce the odds of payment shock, and leave you with a better equity cushion if prices soften after you buy.

The trade-off is liquidity. Cash used for the down payment is cash you cannot use for closing costs, moving expenses, repairs, emergency savings, or rate buydowns. That is why a good house down payment calculator should help you compare financing benefits with the practical reality of how much cash you want to keep in reserve after closing.

This calculator now separates the mortgage result from the cash-to-close result. That matters because two buyers with the same down payment can have very different risk positions if one still has reserves after closing and the other has used nearly every available dollar.

The mortgage payment formula

Monthly principal and interest is calculated using the standard fixed-rate amortisation formula. The result depends on three variables: the loan amount (home price minus down payment), the annual interest rate converted to a monthly rate, and the total number of monthly payments.

This down payment calculator isolates the financing effect of the down payment by keeping the mortgage result focused on principal, interest, loan-to-value ratio, and PMI planning. It then adds a separate cash-planning layer for estimated closing costs and reserves so the user can answer two questions at once: how much does the down payment change the mortgage, and how much cash may still be left after closing?

Understanding private mortgage insurance (PMI)

For US conventional mortgages, PMI is typically required when the down payment is less than 20% of the home price. Annual PMI costs generally range from 0.5% to 1% of the total loan amount, depending on credit score, loan-to-value ratio, and lender policies. This calculator uses 0.75% as a planning estimate.

Under US conventional-mortgage rules, PMI is not permanent. Once you reach 20% equity through payments or appreciation, you can usually request PMI cancellation. Lenders are required to automatically remove PMI when equity reaches 22% based on the original purchase price.

That 20% rule is one reason so many buyers search for a mortgage down payment calculator before they shop seriously. The monthly mortgage payment may look manageable at 5% or 10% down, but the added PMI can materially change the real monthly housing cost until you build enough equity to cancel it.

The PMI section is intentionally labeled as a U.S. conventional planning estimate because other loan programs handle mortgage insurance differently. FHA loans use mortgage insurance premiums with their own rules, while VA and USDA loans use different fee structures and do not follow the same PMI cancellation framework as a conventional loan.

Competitor down payment calculators often use a fixed PMI assumption, but real PMI pricing varies. The calculator therefore lets you adjust the annual PMI estimate instead of forcing the default. If you already have a lender quote, replace the planning rate with the quoted PMI rate before comparing down payment options.

Minimum down payment rules by loan type

A common question is whether 20% is required to buy a house. It is not. For many U.S. borrowers, conventional loans may be available with as little as 3% down, FHA loans commonly use 3.5% down, and some eligible VA and USDA borrowers may qualify for zero-down programs. That means the minimum down payment depends on the loan program, occupancy rules, credit profile, and lender overlays rather than on a single universal threshold.

That said, minimum down payment is not the same as comfortable down payment. A buyer who stretches to meet the minimum may still face a higher monthly payment, higher total interest, and mortgage insurance or funding charges that make the deal feel tight month to month. The comparison table is designed to answer the next question after minimum eligibility: what does each option actually cost me?

If you are comparing FHA, VA, USDA, and conventional options, use this calculator as a first-pass planning tool for the conventional path, then confirm program-specific rules with your lender or the relevant agency guidance. Loan type can change down payment rules, insurance treatment, closing cash requirements, and even the set of properties that qualify.

Down payment versus closing costs and cash reserves

Buyers often focus so heavily on the down payment that they under-budget for everything else needed to close. In practice, you may also need cash for lender fees, title costs, prepaid taxes or insurance, moving expenses, and the first round of repairs or furnishing after you get the keys. A strong down payment plan should leave room for those costs instead of exhausting every dollar on the upfront percentage.

That is why the financially best answer is not always the biggest possible down payment. If increasing your down payment from 10% to 20% wipes out your emergency fund, forces you to carry credit-card debt after move-in, or leaves no margin for maintenance, the lower-payment benefit can be offset by weaker overall household resilience. Many buyers use a savings calculator or emergency-fund plan alongside a mortgage down payment calculator to judge the full cash picture.

The reserve target input is deliberately simple. It does not decide how much cash you should keep, but it does expose whether the selected down payment and closing-cost estimate leave enough money for the cushion you already decided you want. That makes the page more useful for the practical question competitors surface repeatedly: how much should I put down without becoming house-poor?

Worked example: 350,000 home with 10% down

Suppose a buyer is looking at a 350,000 home, plans to put 10% down, chooses a 30-year loan term, and expects a 6.5% interest rate. The upfront down payment would be 35,000, leaving a financed amount of 315,000 and a 90% loan-to-value ratio.

Because the down payment is below 20%, PMI would usually still apply. On the calculator’s planning assumption of 0.75% annually, that adds an estimated 196.88 per month until enough equity is built. Comparing that result with 15% and 20% down makes it easier to judge whether keeping more cash in savings outweighs the higher monthly cost.

In a real buying decision, the next step would be to compare that 10% scenario with the same home at 20% down. The buyer would need an extra 35,000 upfront, but would usually eliminate PMI and reduce the financed amount enough to lower the monthly principal-and-interest payment as well. That trade-off is exactly what this house down payment calculator is designed to surface quickly.

If the buyer can reach 20% only by draining reserves, the 10% option may still be more practical even though it is less efficient on paper. If they can reach 20% while still covering closing costs and keeping a reserve fund, the comparison may justify waiting longer to buy.

With a 3% closing-cost estimate, the 10% option also needs about 45,500 at closing before moving costs or repairs. If the buyer has 55,000 available and wants to keep a 10,000 reserve, the plan is almost fully allocated before the first mortgage payment is due. That is why the calculator shows cash needed at closing and reserve gap next to the mortgage payment rather than treating the down payment as the only upfront number.

Gift funds, assistance, and timing your purchase

Many buyers do not save the entire down payment from income alone. Depending on loan program and lender rules, gift funds from family, employer assistance, state or local down payment assistance, or other approved sources may help bridge the gap. Those options can make a purchase possible sooner, but they often come with documentation requirements, occupancy rules, or limits on how funds are sourced and applied.

Timing also matters. If rates are high, buyers sometimes assume they should always wait for a lower rate before buying. In reality, the better question is whether you can assemble a workable cash position: a realistic down payment, enough money for closing, and enough reserves to handle surprises. This calculator helps with the down payment piece, but the final timing decision should weigh loan terms, housing needs, local inventory, and your broader balance sheet.

What this calculator does not cover

This tool estimates principal, interest, a US conventional PMI planning baseline, and a simplified closing-cost cash estimate only. It does not include property taxes, homeowner insurance, HOA fees, points, moving costs, repair costs, or a lender's final cash-to-close figure. Actual mortgage costs depend on your lender, credit profile, property type, local tax rates, and loan program.

The PMI estimate starts with a 0.75% rate as a planning baseline, but you can replace it with a quoted annual PMI rate if you have one. Your actual PMI rate may differ based on your credit score and lender. For a complete picture, request a Loan Estimate from your lender.

It also does not model FHA mortgage insurance premiums, VA funding fees, USDA guarantee-fee structures, lender-paid mortgage insurance, seller concessions, or down payment assistance program terms. Those details can materially change the minimum cash needed and the ongoing monthly cost.