Down Payment Calculator
Plan your path to homeownership by calculating your required down payment. See how long it will take to save based on your current savings, monthly contributions, and savings rate.
The down payment is the cash you bring to closing — the slice of the purchase price you pay up front instead of borrowing. Everything else flows from this number: your loan amount, your monthly payment, whether you owe private mortgage insurance, and which loan programs you even qualify for.
This calculator answers two questions at once. First, how much cash do you actually need to hit a given percentage of the home price? Second, given what you already have saved and what you can put away each month, how long until you get there?
It uses standard future-value math — your current savings compound at the APY you enter, and your monthly contributions are added each month and compound on top — to project the month you'll cross the down-payment threshold. The result is a planning estimate; treat it as a target date, not a guarantee.
Inputs
Results
Down Payment Needed
$70,000
Still Need to Save
$55,000
Months to Goal
48
Interest Earned
$7,436
Savings Progress
Down Payment Funding
Savings Timeline
| Month | Contribution | Interest | Balance |
|---|---|---|---|
| 1 | $1,000.00 | $56.25 | $16,056.25 |
| 6 | $1,000.00 | $76.20 | $21,397.21 |
| 12 | $1,000.00 | $100.65 | $27,939.72 |
| 18 | $1,000.00 | $125.64 | $34,630.82 |
| 24 | $1,000.00 | $151.21 | $41,473.88 |
| 30 | $1,000.00 | $177.36 | $48,472.37 |
| 36 | $1,000.00 | $204.10 | $55,629.81 |
| 42 | $1,000.00 | $231.44 | $62,949.80 |
| 48 | $1,000.00 | $259.41 | $70,000.00 |
Formula
How to use this calculator
- Enter the home price you are targeting. Use a realistic local-market number — the listing price you would actually expect to win, not the cheapest comp.
- Set the down payment percentage. 20% avoids PMI on conventional loans; 5% is a common conventional minimum; 3.5% qualifies for FHA; 0% is possible on VA and USDA loans for eligible borrowers.
- Enter your current savings earmarked for the down payment. Do not include your emergency fund — lenders expect cash reserves separate from the down payment.
- Enter the amount you can realistically save each month. Be conservative: it is better to beat the projection than to miss it.
- Enter the APY of the account holding the savings. A high-yield savings account or short-term CDs are typical; do not enter equity-market returns — down-payment money should not be in stocks.
- Review the target dollar amount, the projected month you cross it, and how much of the total comes from contributions vs. interest earned.
- If the timeline is too long, adjust the down payment percentage downward or the monthly savings upward and re-run.
- Remember to budget for closing costs (2–5% of the home price) on top of the down payment. Lenders require both at closing.
Worked examples
Saving for 20% on a $400,000 home
Target: $400,000 × 20% = $80,000 Current savings: $10,000 Monthly savings: $1,500 APY: 4.5% Months to reach goal: about 41 months (3 years, 5 months) Of the $80,000, roughly $74,500 comes from contributions and $5,500 from interest.
FHA route — 3.5% on the same home
Target: $400,000 × 3.5% = $14,000 Current savings: $10,000 Monthly savings: $1,500 APY: 4.5% Months to reach goal: about 3 months — almost immediate. Trade-off: FHA loans require Mortgage Insurance Premium (MIP) for the life of the loan in most cases. Buying $90,000 of house with less cash on hand means paying MIP for decades. Calculate the lifetime cost before choosing the smaller down payment.
When raising the savings rate beats raising the percentage
Target: $80,000 (20% on $400,000) Scenario A: $1,000/mo at 4.5% APY → 70 months Scenario B: $1,500/mo at 4.5% APY → 48 months Scenario C: $1,000/mo at 0.5% APY (low-yield account) → 80 months Moving from a 0.5% checking account to a 4.5% high-yield account shaves about 10 months. Adding $500/mo to contributions shaves about 22 months. Contribution amount matters more than rate at this time horizon.
When to use this calculator
Use this calculator early in the home-buying journey — before you talk to a lender, before you pick a neighborhood, ideally before you even know which city you'll buy in. Knowing the target dollar amount and a realistic save-by date is what turns "someday" into a budget line item.
The output is most useful when paired with two other tools: the home affordability calculator to confirm the target home price is one you'd actually qualify for given your income and debt, and the mortgage payment calculator to confirm the monthly payment at that price and down-payment combo fits your budget.
The output is least useful for predicting market conditions. It assumes the home price stays flat while you save. In a market where home prices are rising 5%+ per year, the target moves up while you save — so consider running the calculator with the home price inflated to a realistic future value, not today's listing.
Common mistakes to avoid
- Confusing the down payment with the cash needed at closing. Closing costs (lender fees, title, prepaid taxes and insurance, escrow funding) add another 2–5% of the home price on top of the down payment.
- Saving the down payment money in a checking account or a brokerage. Checking earns nothing; a brokerage exposes the money to a market drawdown right when you need it. Use a high-yield savings account, money market fund, or short-term Treasuries.
- Forgetting that PMI ends. A 10%-down conventional loan adds PMI, but PMI typically drops off automatically once the loan-to-value reaches 78%. The "20% to avoid PMI" rule is sometimes worth less than people think.
- Treating gift funds as informal. Family gift money toward a down payment requires a signed gift letter and paper trail; lenders will reject undocumented deposits during underwriting.
- Tapping a 401(k) loan for the down payment without modeling the cost. The loan must be repaid (usually within 5 years) with after-tax dollars, and if you leave the job it often becomes due immediately or is treated as a taxable distribution.
- Counting your emergency fund as part of the down payment. Lenders want to see cash reserves remaining after closing — usually 2–6 months of mortgage payments. Spending your last dollar to close is a red flag.
Frequently Asked Questions
Sources & further reading
- Buying a House — step-by-step guide — U.S. Consumer Financial Protection Bureau
- FHA Loan Requirements — U.S. Department of Housing and Urban Development
- VA Home Loan benefits and eligibility — U.S. Department of Veterans Affairs
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