Mortgage Calculator: Housing Fund Loan 30-Year Equal Installment, Commercial Loan 4.2% 1M 30-Year Amortization CSV
Calculate commercial, provident-fund or combined mortgages with both equal-installment and equal-principal methods. View the monthly payment, total interest, full month-by-month amortization schedule and a payment-trend chart, then model prepayment that either shortens the term or reduces the monthly payment. Export the schedule to CSV and save scenarios to local history — everything runs in your browser.
Parameters
Input Parameters
Result
Result Overview
Amortization schedule
Amortization Schedule
Monthly trend
Monthly Trend
Prepayment simulation
Prepayment Simulation
How to Use
Mortgage Calculator Guide
Commercial / Provident Fund / Combined Loans
The mortgage calculator is the core tool in FinCompute’s financial module, designed for first-time buyers, upgraders, property investors and household financial planners. It fully supports commercial loans, housing provident fund loans and combined loans, with both equal-installment and equal-principal repayment methods, plus a built-in early-repayment simulator. It instantly produces the monthly payment, total interest, total repayment, principal/interest composition, a complete monthly amortization schedule and trend charts. All computation runs locally in your browser — sensitive figures such as loan amounts and rates never leave your device, making it safe to experiment repeatedly before a purchase decision.
01 Loan types and repayment methods
There are three loan types. A commercial loan is a standard bank mortgage whose rate references the LPR plus the bank’s spread based on your credit profile. A provident fund loan draws on your housing fund account and usually carries a significantly lower rate, but the amount is capped by your contribution base and local policy. A combined loan stacks both — ideal when the provident fund alone cannot cover the purchase — with each portion charged its own rate and the monthly payments summed. The relevant amount and rate fields appear automatically once you choose a type.
Two repayment methods are supported. Equal installment (annuity) keeps the monthly payment fixed, with interest dominating the early months — best for borrowers with stable income who want predictable household cash flow. Equal principal repays a fixed principal slice each month, so the payment starts high but declines and total interest is lower — best for those who can afford early installments and want to minimize interest cost. Monthly payment, total interest and total repayment for both methods are shown side by side for easy comparison.
- Commercial reference rate: 3.85% (LPR baseline), editable to your contract rate
- Provident fund reference rate: 2.85%, varies slightly by locality
- Loan term: 1–40 years, typically 20–30 years
- Combined loan: commercial + provident fund principal, monthly payment is the sum of both
02 Filling parameters and reading results
Start by choosing the loan type and repayment method, then enter the principal, term and the relevant rates. Amounts are in yuan and accept large figures; rates accept two decimal places (e.g. 3.85 means 3.85% annual). For a combined loan you must enter both portions. After clicking Calculate, the right panel shows four key metrics: monthly payment (a fixed value for equal installment, or the first-month payment for equal principal), total repayment, total interest and the original principal, with a principal/interest bar visualizing their ratio.
Below, the amortization schedule lists each month’s payment, principal, interest and remaining balance with pagination, and can be exported to a CSV file that opens in Excel or WPS for archiving or discussion with a loan officer or family. The trend chart is an SVG line graph showing how principal and interest evolve over time; under equal principal you can clearly see interest declining month by month while principal stays flat.
03 Formula reference
Equal installment uses the annuity formula: M = P × r(1+r)^n / [(1+r)^n − 1]. Equal principal first-month payment = P/n + P×r, decreasing by P×r/n each month. Here P is principal, r is the monthly rate (annual rate ÷ 12), and n is the number of months (term × 12). A combined loan sums the two portions. Because monthly amounts are rounded to the nearest cent, the final month may differ by a few cents.
Loan type & method
- CommercialStandard bank mortgage; enter the commercial amount and its rate.
- Provident fundHousing-fund loan at a lower rate; enter fund amount and rate.
- CombinedStacks both loans; all four amount/rate fields are shown.
- Equal installmentFixed monthly payment (annuity).
- Equal principalFixed principal slice; payment starts high and declines.
Inputs
- amountLoan principal in yuan (separate fields for combined loans).
- rateAnnual interest rate in percent (e.g. 3.85 means 3.85%).
- yearsLoan term, 1–40 years.
Actions
- CalculateComputes monthly payment, totals, chart and schedule.
- ResetRestores the default input values.
- ExportDownloads the amortization schedule as a CSV file.
- All results are estimates; please defer to your bank’s official approval and statements
- For a combined loan early repayment, prioritize the higher-rate commercial portion
- LPR may adjust each year; edit the rate field directly to model the latest policy
- Second-home rates are usually LPR plus a spread — enter your actual contract rate
- The schedule is rounded to the cent; cumulative rounding may cause a few yuan of deviation
- For a 1M commercial loan at 4.2% over 30 years, just adjust the defaults to estimate the monthly payment instantly
- The exported CSV amortization schedule works for mortgage paperwork and long-term household budgeting
Early Repayment Simulator Guide
Shorten term / Reduce monthly payment
The early repayment simulator helps you assess the financial benefit of partially prepaying your mortgage. When you receive a bonus, have idle cash or want to reduce long-term debt, enter the prepayment amount and the number of months already paid, then choose between “shorten the term” and “reduce the monthly payment.” The tool instantly computes the interest saved, the adjusted monthly payment and the remaining term, giving you quantitative support for your decision. It models the main loan’s principal, rate and method; combined loans are estimated using a weighted average rate.
01 Two strategies
Shorten the term keeps your original monthly payment unchanged and applies the prepaid amount directly to the remaining principal, cutting the total repayment period. This strategy saves more interest because the interest-bearing base drops for all subsequent months — ideal if your monthly budget is comfortable and you want to become debt-free sooner.
Reduce the monthly payment keeps the original maturity date fixed and re-amortizes the lower remaining principal over the remaining months, lowering each payment. It saves slightly less interest but markedly eases monthly cash flow — ideal if you expect large expenses, have variable income or want to improve liquidity. You can switch between the two strategies freely and instantly compare interest saved, the new payment or the months shortened.
- Prepayment amount: the lump-sum principal repaid (yuan), must be positive
- Months already paid: elapsed months of the main loan, sets the starting balance
- Strategy: shorten term (more interest saved) or reduce payment (lower monthly burden)
- Combined loans use a weighted-average rate; banks calculate each portion separately in practice
02 Reading results and advice
The result panel shows interest saved (highlighted in green), the new total repayment, remaining months, and either the months shortened or the new monthly payment. The larger the interest saved, the more beneficial the prepayment. You can iterate on the amount, elapsed months and strategy to find the most efficient use of your cash. Generally, prepaying earlier in the loan saves more interest because the remaining principal is larger; near the end of the term, savings become marginal.
Strategy
- Shorten termKeeps the monthly payment unchanged and cuts the repayment period (more interest saved).
- Reduce paymentKeeps the term unchanged and lowers each monthly payment (better cash flow).
Inputs
- prepay amountLump-sum principal to repay early, in yuan (must be positive).
- months paidElapsed months of the main loan; sets the starting balance.
- Some banks limit early repayment by count or timing (e.g. only after one year) — ask your loan officer first
- A penalty may apply, typically 0.5%–3% of the prepaid amount
- Under long-term inflation the real cost of debt may be lower than nominal interest — weigh both sides
- This simulator excludes penalties and fees; factor in your bank’s specific policy
- If your investment return consistently exceeds the loan rate, keeping the cash invested may beat prepaying
A home is the largest purchase most people ever make. This free online mortgage calculator turns the standard amortization formulas into three simple inputs so you get a complete, verifiable payment plan in 30 seconds — whether you need a housing-fund loan 30-year equal-installment monthly payment or a commercial loan 4.2% on 1 million over 30 years with a CSV export.
Commercial, housing provident fund and combined loans
Commercial loans priced off the LPR or your bank's quoted rate; housing provident fund loans, which usually carry a lower rate but a capped amount; and combined loans, where the commercial and provident portions are computed separately with their own rates and terms, then merged into a single monthly payment — matching what your bank produces, including second-hand home provident-fund combined loan comparison.
Equal installment vs equal principal side by side, total interest compared
Equal installment (annuity) keeps your monthly payment flat, with interest dominating the early months. Equal principal repays a fixed slice of principal each month, so total interest is lower but the initial payment is higher. FinCompute shows both side by side so you can compare equal-installment vs equal-principal total interest at a glance.
Early repayment simulator: shorten term vs reduce payment, how much interest prepaying 200k saves
When you have a bonus or spare cash, you can either shorten the term or reduce the monthly payment. Enter the prepayment amount and how many months have elapsed; the calculator instantly shows the interest saved and the months shortened (or the new monthly payment), answering "which year of a 30-year mortgage saves most" and "how much interest does prepaying 200k save".
Principal/interest pie chart, trend line and amortization schedule CSV export
The principal/interest chart reveals how much of each payment is truly interest; the trend line shows how that mix evolves over the life of the loan; the paginated schedule exports to CSV for archiving — with every month’s payment, principal, interest and remaining balance — for discussions with your bank and family.
Mortgage payment formula: equal installment, equal principal and combined loans
Equal-installment monthly payment = P · r(1+r)^n / ((1+r)^n − 1). Equal-principal first-month payment = P/n + P·r, then decreases by P·r/n each month, where P is principal, r is the monthly rate (annual rate ÷ 12) and n is the number of months. For combined loans, the two parts are summed. A common rule: keep the mortgage payment under 30%–40% of take-home pay.
FAQ
QWhich repayment method is better, equal installment or equal principal?
Equal principal costs less in total interest but has a much higher first payment. Equal installment keeps monthly payments flat and is easier to budget around. Pick equal installment if you want predictable cash flow, and equal principal if you can front-load larger payments and want to minimize total interest.
QHow are combined loans calculated?
The commercial portion and the provident-fund portion are calculated independently using their own principal, rate and term. Their monthly payments, principal and interest are then added together for each row, producing a schedule that matches a combined-loan bank statement.
QWhen prepaying, should I shorten the term or reduce the monthly payment?
Shortening the term usually saves far more interest, because the principal is paid down faster. Reducing the payment lowers your monthly burden but saves less overall. Choose term reduction if your income is stable and you want to be debt-free sooner.
QWhy is my bank's monthly payment slightly different from the result here?
Differences usually come from (1) using the latest LPR plus spread, (2) the bank's day-count convention (30/360 vs actual days), or (3) the first payment covering a partial month after disbursement. This tool gives the canonical annuity result; banks may round or adjust the first/last installment.
QHow much can I borrow from the housing provident fund?
Caps vary by city. A common pattern is RMB 500k–600k for an individual and RMB 800k–1.2M for a couple, but local rules change frequently. Enter the actual approved amount into the tool and check with your local provident-fund center for the exact cap.
QWhere can I check the current LPR?
The Loan Prime Rate is published monthly (usually on the 20th) by the National Interbank Funding Center, and is reposted by the People's Bank of China and major banks. The tool defaults to 3.85%; replace it with the rate written in your actual loan contract.
QCan I export the amortization schedule?
Yes. Click "Export CSV" on the schedule card to download a file with monthly payment, principal, interest and remaining principal. It opens cleanly in Excel, Numbers or WPS.
QDoes it support second-home rates?
Yes. Just type the actual annual rate shown in your second-home loan contract into the commercial or provident rate field — the calculator uses whatever rate you supply.
QHow much interest can I save by prepaying 200,000 yuan?
Enter 200,000 as the prepayment amount and the number of months already paid, then choose a strategy. The simulator instantly shows the interest saved and either the months shortened or the new monthly payment. The earlier in the loan you prepay, the larger the saving, because the remaining interest-bearing principal is larger.
QIs it better to shorten the term or reduce the monthly payment?
Shortening the term generally saves far more interest because the principal is paid down faster. Reducing the payment lowers your monthly cash burden but saves less overall. Choose term reduction if your income is stable; choose payment reduction if you need liquidity or expect large expenses.
QHow do I calculate a combined loan early repayment?
This tool models the combined loan using a weighted-average rate across the commercial and provident portions. In practice banks apply each prepayment to a specific portion — prepaying the higher-rate commercial portion first usually saves the most. Use the result as a planning estimate and confirm the allocation rule with your bank.
QCan I download a 30-year amortization schedule as CSV?
Yes. Run the calculation and click "Export CSV" on the schedule card. The file lists every month’s payment, principal, interest and remaining balance, and opens cleanly in Excel, Numbers or WPS for archiving or sharing with a loan officer or family member.
QWhat is the monthly payment on a 1 million yuan commercial loan at 4.2% over 30 years?
Choose commercial loan + equal installment, enter 1,000,000 principal, 4.2% annual rate and 30 years. The calculator returns the fixed monthly payment, total interest and full schedule. You can then switch to equal principal to compare the higher first payment against the lower total interest.
QHow do I check the latest LPR mortgage rate?
The Loan Prime Rate is published monthly (around the 20th) by the National Interbank Funding Center and reposted by the People’s Bank of China and major banks. Replace the default commercial rate with the latest 5-year-and-above LPR plus the spread your bank quoted.
QCan I convert a commercial mortgage to a housing-provident-fund loan?
Some cities allow business-to-provident conversion after you meet local conditions (e.g. the property is delivered, the provident fund has been paid continuously for 6–12 months and the original bank consents). Policies and caps vary city by city; check with your local provident-fund center. In the calculator you can model the new lower-rate loan directly using the provident rate.