Down Payment Calculator
Down Payment Calculator
The cash you need on the day you buy a home — the down payment plus stamp duty, registration and other costs — and how long it takes to save, or what to save each month, while the price keeps moving.
Cash needed to buy
A $80,00,000 home, 20% down, stamp duty and registration 6%, $1,00,000 other costs; $5,00,000 saved, $50,000 a month at 7%, prices rising 4% a year
Cash needed and the saving plan
- P, d, s, O
- the price, the down-payment share, the stamp-duty-and-registration share, the other costs
- H, M
- what you have saved, and the monthly saving (added at the end of each month)
- i, g
- the monthly return (annual ÷ 12) and the yearly price growth
- months
- with no price growth, m = ln[(Cash × i + M) ÷ (H × i + M)] ÷ ln(1 + i), rounded up. With growth there is no closed form: the page halves an interval proven to contain the first month savings catch the target 40 times. Monthly saving for N months: M = [Cash × (1 + g)N/12 − H(1 + i)N] × i ÷ [(1 + i)N − 1].
Worked example
A $80,00,000 home, 20% down, stamp duty and registration 6%, $1,00,000 other costs; $5,00,000 saved, $50,000 a month at 7%, prices rising 4% a year
Down payment 20% = $16,00,000; stamp duty and registration 6% = $4,80,000; other $1,00,000
Cash needed at today's price = $21,80,000; still to save $16,80,000
If the price stood still: m = ln[(21,80,000 × 0.005833 + 50,000) ÷ (5,00,000 × 0.005833 + 50,000)] ÷ ln(1 + 0.005833) = 29.2, so 30 months
With prices rising 4% a year: 34 months, when savings of $24,83,616 pass the cash then needed, $24,36,226
To buy in 36 months instead: save $45,974 a month ($39,157 if the price stood still)
Cash needed on an 80 lakh home with 1 lakh of other costs, by down payment and stamp duty rate
| Down payment | Stamp duty + registration 5% | 6% | 8% |
|---|---|---|---|
| 10% | $13,00,000 | $13,80,000 | $15,40,000 |
| 20% | $21,00,000 | $21,80,000 | $23,40,000 |
| 25% | $25,00,000 | $25,80,000 | $27,40,000 |
| 30% | $29,00,000 | $29,80,000 | $31,40,000 |
The cash a home really needs
The down payment is only part of the cash you need on the day. Stamp duty and registration are charged on the price and paid by the buyer, and lenders cannot fold them into an Indian home loan’s value except on the cheapest homes, so they come from savings too, with legal fees, brokerage and the loan’s processing fee. In the example, 20% down on $80,00,000 is $16,00,000, but the cash needed is $21,80,000. The rate of stamp duty depends on your state or country and sometimes on who is buying; the page takes your figure and claims none.
How big the down payment must be. In India the Reserve Bank caps a housing loan at 90% of the property’s cost up to ₹30 lakh, 80% up to ₹75 lakh and 75% above, so the down payment is at least 10%, 20% or 25% depending on the loan; the loan-to-value calculator works out the exact minimum. A bigger down payment means a smaller loan, a lower EMI and less interest, and some lenders charge a lower rate at a lower LTV; the loan affordability calculator shows the price a given EMI and down payment support.
Saving it while the price moves. If the home’s price rises while you save, the target moves away from you. This page grows the whole cash need by the price growth you enter, compounded monthly, and counts your savings at the monthly return you enter. With no price growth the months to save have a closed form with a logarithm: 30 months in the example. At 4% price growth it takes 34 months, because the target rises by then. If prices grow faster than your savings earn, a small monthly amount may never catch up; the page says so rather than showing a date. Planning by target date instead gives the monthly saving that lands exactly on the grown figure.
Money you need within a few years is usually kept where it cannot fall in value, so enter a deposit-like return after tax; the RD calculator shows a recurring deposit, and the savings goal calculator a goal with no home attached. Price growth is a guess: nobody knows next year’s home prices, so try a few figures, including zero. This is arithmetic on the figures you enter, not financial advice.
Frequently asked questions
How much cash do I need to buy a house?
The down payment plus stamp duty, registration and other one-off costs. On a $80,00,000 home with 20% down, 6% duty and registration and $1,00,000 of other costs, $21,80,000.
What is the minimum down payment for a home loan in India?
10% for a loan up to ₹30 lakh, 20% for a loan above ₹30 lakh up to ₹75 lakh and 25% above that, because RBI caps the loan at 90%, 80% and 75% of the cost. Stamp duty and registration are on top.
How long will it take to save a down payment?
With $5,00,000 saved and $50,000 a month at 7%, 30 months if prices hold still and 34 if they rise 4% a year, for the example’s $21,80,000.
Does the calculator allow for rising house prices?
Yes. It grows the whole cash need, costs included, by the growth rate you enter, every month you wait. Enter 0 to plan at today’s price.
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References
- Reserve Bank of India. Master Circular – Housing Finance. RBI/2025-26/16, DOR.CRE.REC.No.12/08.12.001/2025-26, 1 April 2025 (banks), since consolidated into the Reserve Bank of India (Commercial Banks – Credit Facilities) Directions, 2025, 28 November 2025. Individual housing loans: LTV not above 90% up to ₹30 lakh, 80% above ₹30 lakh to ₹75 lakh, 75% above ₹75 lakh; stamp duty, registration and other documentation charges excluded from the cost of the house, except where that cost does not exceed ₹10 lakh.
- Reserve Bank of India. Reserve Bank of India (Housing Finance Companies) Directions, 2025. 28 November 2025, para 58: the same three LTV ceilings (90%, 80%, 75%) and the same ₹10 lakh rule for stamp duty and registration, for housing finance companies.
- Brealey RA, Myers SC, Allen F. Principles of Corporate Finance. McGraw-Hill. The present value of an annuity, from which the level-payment loan formula, its schedule and its inverse follow.
- Central-bank inflation targets used as default inflation by currency: Reserve Bank of India (4% CPI, flexible inflation targeting framework); U.S. Federal Reserve (2% PCE); European Central Bank (2%); Bank of England (2% CPI); Bank of Canada (2%); Reserve Bank of Australia (2–3%); Bangko Sentral ng Pilipinas (3% ± 1). Actual inflation often runs above target.