How this calculator works
Enter separate principal and rates for commercial and housing provident-fund tranches. Choose equal principal and interest or equal principal, and optionally model one lump-sum prepayment in a selected month.
Calculation method
Equal principal and interest uses the standard fixed-rate amortisation formula. Equal principal repays the same principal each month. A prepayment is allocated in proportion to tranche principal and keeps the planned payment or principal amount, shortening the term.
Check before using the estimate
The editable 3.50% commercial default is the over-five-year LPR published on 20 July 2026; 2.60% is the first-home over-five-year provident-fund rate effective 8 May 2025. Use the local eligibility, quota, contract spread, penalty and approval terms for the actual mortgage.
Worked example
Defaults: commercial principal ¥1,400,000, annual rate 3.50%, 30-year term (360 periods), equal principal and interest, no provident-fund tranche, no prepayment.
| Item | Calculation | Amount |
|---|---|---|
| Monthly rate | 3.50% ÷ 12 | 0.2917% |
| Monthly payment | ¥1,400,000 × 0.2917% × (1+0.2917%)^360 ÷ ((1+0.2917%)^360 − 1) | ¥6,286.63 |
| Total interest | ¥6,286.63 × 360 − ¥1,400,000 | ≈ ¥863,185 |
| Total paid | Principal + interest | ≈ ¥2,263,185 |
Adding a ¥500,000 provident-fund tranche at 2.60%: provident-fund payment about ¥2,003, combined monthly payment about ¥8,290, lower total interest.
Input variations
| Change | Comparison item | Result | vs default |
|---|---|---|---|
| Switch to equal principal | First / last month payment | ¥7,583 / ¥3,900 | Higher early, decreasing monthly |
| Switch to equal principal | Total interest | ≈ ¥733,000 | Saves ¥130,000 |
| Switch to 25-year term | Monthly payment / total interest | ¥7,004 / ¥701,000 | Payment +¥717, saves ¥162,000 |
| Add ¥500,000 prepayment (month 60) | Remaining term / interest saved | 209 months / ¥520,000 | From 360 to 209 months |
Equal principal carries higher early burden and lower total interest; equal instalments keep payment constant with more total interest. Prepayment with the original payment shortens the term; lenders may instead offer a "reduce payment" option that produces a different result.
Differences from official documents
Differences from actual bank repayment arise because: real rates often include spreads (e.g. LPR+55bp = 4.05%); repricing dates reset annually or quarterly, changing the payment after repricing; banks accrue interest daily and use actual-day counts; prepayment may be offered as "shorten term" or "reduce payment" and the tool defaults to shorten; prepayment penalties may apply (1–3% of remaining balance or contractually waived); provident-fund loan amounts are capped by city rules.
Thresholds and limits
Default commercial rate 3.50% (over-five-year LPR on 2026-07-20, editable); default provident-fund rate 2.60% (first-home over-five-year from 2025-05-08; second-home over-five-year minimum is 3.075%, editable); term 1–30 years; commercial and provident-fund principal each ¥0–¥100,000,000; prepayment amount cannot exceed total tranche principal. LPR is published monthly; the tool updates defaults when the over-five-year tenor changes. Provident-fund rates take effect by PBOC notice.
Documents to check
Loan contract (rate, spread, repricing date, prepayment terms, penalty terms); bank-issued repayment schedule; monthly repayment SMS or app notification (verify actual payment); provident-fund centre loan statement; prepayment application and penalty confirmation (if applicable); property ownership certificate and purchase contract (verify property basics).
Confirm both repayment method and prepayment objective
Equal instalment, equal principal and prepayment scenarios have different cash-flow shapes.
Equal instalment is level; equal principal declines
Commercial and provident-fund tranches are calculated separately then combined, so their rates and balances remain visible.
This prepayment scenario shortens the term
It preserves planned repayment intensity after allocating the lump sum. A lender option that lowers payment while keeping the term will differ.