Down Payment Calculator · filed Oct 9, 2026
How much do I need to buy a house?
The down payment is only the first line. The full cash picture has three lines: the down payment, the closing costs, and the reserves you keep after the keys. Here they are on a $400,000 home at 7% on a 30-year conventional loan, with closing costs at 3% and a prudent 3-month reserve of the full monthly payment.
The whole cash picture
| Down | Down payment | Closing (3%) | 3-mo reserve | Total cash |
|---|---|---|---|---|
| 3.5% | $14,000 | $12,000 | $10,123 | $36,123 |
| 10% | $40,000 | $12,000 | $9,203 | $61,203 |
| 20% | $80,000 | $12,000 | $7,937 | $99,937 |
Reserves are 3 months of the full monthly payment (P&I, tax, insurance, PMI) at each down level. Not every lender requires a stated reserve; budget it anyway.
Which dollars you get back
- The down payment is not spent — it becomes your equity on day one. Sell the house and (prices cooperating) it comes back.
- The closing costs are spent. Lender fees, title, and recording are gone the moment you sign. This is the true price of the transaction, and the number to minimize when comparing lenders.
- The reserves are not spent — they stay in your account as the buffer for the first surprise repair or the first thin month.
The lines people forget
Earnest money (usually 1–2% with the offer) is not an extra cost — it credits toward your down payment at closing. Prepaid items (interest to month-end, escrow reserves for tax and insurance) inflate the closing disclosure without being lender fees; when you compare lender quotes, ask for the numbers without them. Moving, immediate repairs, and the first month’s overlap with rent are real cash outflows that no disclosure shows.
The savings target, dated
The number that matters for planning is the total cash column. At $1,500 a month saved, the 3.5%-down picture ($36,123) dates at about 25 months; the 10%-down picture ($61,203) at about 41 months; the 20%-down picture ($99,937) at about 67 months. Date yours in the Down Payment Calculator — the seal posts the cash and the months side by side.
Savings-month math: $36,123 / $1,500 = 24.1 → 25 months; $61,203 / $1,500 = 40.8 → 41 months; $99,937 / $1,500 = 66.6 → 67 months.
Filed under down payments
- Down Payment CalculatorRun the ladder at your price, rate, and loan program.
- How Much Down Payment on $400k?The four standard checks — 3.5%, 5%, 10%, 20% — posted line by line.
- Is 20% Down Necessary?The myth, the PMI math, and the wait-it-out arithmetic.
- FHA Down Payment Requirements3.5% at 580+, 10% at 500–579, and the two MIP premiums priced out.
- Down Payment vs PMI CostWhen the bigger check beats the insurance, and when it doesn’t.