House price calculator
Turn a unit price and floor area into a total price, then compute the loan amount, monthly payment and total interest from the down payment, term and rate, with equal-installment, equal-principal and housing-fund combination loans.
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Result
Total price, down payment, monthly payment and interest.
Enter a unit price and area to calculate
Total price: 0 · Down payment: 0 · Loan amount: 0 · Monthly payment: 0 · Total interest: 0
What this tool does
- Estimate on the spot: enter the unit price and floor area to see the total, the down payment and whether the monthly payment fits your budget.
- Compare equal-installment with equal-principal: the latter saves interest but front-loads the payments, and the difference is visible immediately.
- Model a housing-fund combination loan: enter the fund quota and rate, and the remainder is priced at the commercial rate.
- Work backwards from an affordable monthly payment by adjusting the down payment share and the term.
Example
Input
30000,100
Output
房屋总价：3000000.00 元（30000 元/㎡ × 100 ㎡） 首付 30%：900000.00 元 贷款总额：2100000.00 元 贷款期限：30 年（360 期） 还款方式：等额本息 每月月供：8967.34 元（等额本息，公式 M = P·i·(1+i)^n / ((1+i)^n − 1)） 利息总额：1128243.98 元 还款总额：3228243.98 元
Equal-installment payment M = P·i·(1+i)^n / ((1+i)^n − 1), with i = annual rate / 12 and n = months.
Frequently asked questions
How is the monthly payment computed?
Equal-installment uses the standard annuity formula: M = P × i × (1+i)^n / ((1+i)^n − 1), where P is the principal, i = annual rate ÷ 12 and n = months (years × 12). At a zero rate it reduces to P ÷ n. For 2.1 million at 3.1% over 30 years, i = 0.00258333 and n = 360, giving about 8967.34 per month.
How much do the two methods differ?
Equal-principal repays a fixed principal amount (P ÷ n) each month, so interest falls month by month and the first payment is the largest; total interest = P × i × (n+1) ÷ 2, an arithmetic series. For 2.1 million at 3.1% over 30 years, equal-installment costs about 1.128 million in interest against 979 thousand, saving roughly 150 thousand but raising the first payment by about 2290.
How are combination loans handled?
The housing-fund part and the commercial part are computed separately and added. Enter the fund quota in yuan and the fund rate; the quota cannot exceed the total loan, which raises an error.
What is the optional third input?
The total price in yuan. Some listings quote a total rather than a unit price; when given it takes precedence and the unit price × area result is ignored.
Which rate should I enter?
The 3.1% default is simply a common recent commercial rate; your contract decides. First homes, second homes, housing fund and commercial loans all differ, so enter your own figures.
Can this be used to sign a contract?
No. It is only the mathematical result of the formulas and excludes bank fees, insurance and early-repayment penalties, and it is not a lending commitment.
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