Down Payment Savings Calculator
Calculate how long it will take to save your down payment goal given monthly savings contributions and interest.
How to use this tool
- Enter target home price, down payment target, current savings toward down payment, monthly savings contribution and savings account rate in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your months to goal and the full breakdown beneath it.
Saving for a down payment is a marathon — knowing your timeline helps you stay on track. Earning interest accelerates the goal, especially over multi-year timelines.
⚠ This tool provides general estimates for education only and is not financial, tax or legal advice. Figures may not reflect your situation — verify with a qualified professional.
Formula
Down Payment Goal = Home Price × (Down Payment % ÷ 100)
Gap = Down Payment Goal − Current Savings
When the savings rate is 0%: Months to Goal = ⌈Gap ÷ Monthly Contribution⌉
When a savings rate applies, the balance is grown month-by-month: Balancen = Balancen−1 × (1 + r) + Monthly Contribution until Balance ≥ Goal, where r = annual rate ÷ 12 ÷ 100.
How it works
This calculator first computes the target down payment from a percentage of the home price, then determines how many months of saving are required to close the gap between current savings and that goal. With a non-zero interest rate it simulates month-by-month compound growth on the running balance plus contributions; with a 0% rate it uses simple division.
The simulation caps at 600 months (50 years) and returns 9,999 if the goal is unreachable. Results assume a fixed monthly contribution and a constant rate; actual savings account rates fluctuate over time.
Worked example
- Down payment goal = $400,000 × 20% = $80,000
- Gap = $80,000 − $20,000 current savings = $60,000
- Savings rate = 0%, so months = ⌈$60,000 ÷ $1,500/mo⌉ = ⌈40⌉ = 40 months
- Interest earned = $0 (0% rate)
Down payment goal: $80,000 | Gap: $60,000 | Months to goal: 40 | Interest earned: $0
Common mistakes to avoid
- Targeting only the down payment percentage while ignoring closing costs (2-5% of the loan) and the cash reserve most lenders require after closing.
- Using a nominal savings interest rate without accounting for the fact that a HYSA or money-market rate changes monthly, so the compounding projection will diverge from reality over 2+ years.
- Forgetting that the home price target itself will grow with appreciation during the savings period, meaning the goal amount should be adjusted periodically.
Key terms
- Down payment
- The portion of the purchase price paid in cash at closing; the remainder is financed via a mortgage.
- Down payment percentage
- The down payment expressed as a percentage of the home price; conventional loans commonly require 3–20%.
- Compound interest
- Interest calculated on both the principal balance and previously accumulated interest; here applied monthly to the growing savings balance.
- PMI threshold
- A down payment below 20% on a conventional loan typically triggers Private Mortgage Insurance (PMI), adding a monthly cost.
- Savings gap
- The difference between the down payment goal and current savings already set aside; the amount that must still be accumulated.
Frequently asked questions
- How much do I need for a down payment?
- Conventional loans typically require 5–20% down. Putting 20% down avoids PMI and gives you more equity from day one. FHA loans require 3.5% but add mortgage insurance. Some first-time buyer programs allow 0–3% down.
- Where should I keep my down payment savings?
- Keep the funds in a high-yield savings account or money market — FDIC insured, liquid, and earning interest. Avoid investing in stocks for a near-term goal, as market volatility could delay your timeline.