Separate estimates from settlement figures
Results here are for estimating and comparing before you commit; they do not replace the official figures from a bank, tax authority or doctor. Actual mortgage payments depend on the disbursement date, interest conventions and the bank’s rounding, so a few yuan of difference is normal. Income tax depends on special deductions, annual settlement and local rules, and health metrics are estimates. Treat every number as a range, not a conclusion.
Mortgages: reading the two repayment styles
Equal instalments keep the monthly payment constant, put more interest early and cost more overall — good when income is stable and predictability matters. Equal principal keeps the principal constant, so payments decline and total interest is lower, at the cost of heavier early months. Focus on three numbers: first payment, total interest, total repayment. When judging early repayment, note that most banks charge interest on the remaining principal, so paying sooner saves more — but some contracts carry penalties, so read them first.
Salary and tax: how take-home pay is built
Take-home pay equals gross salary minus your share of social insurance and housing fund, minus income tax. Tax is withheld cumulatively through the year, so a month with a higher salary can show a bigger deduction — that is expected, not an error. Annual bonuses can be taxed separately or folded into comprehensive income, and the gap can reach thousands of yuan, so compute both before choosing. Special additional deductions (children’s education, mortgage interest, supporting parents) meaningfully reduce taxable income — declare them truthfully through official channels.
Health metrics: useful for trends, not for diagnosis
BMI is a weight-to-height ratio that does not apply to athletes, pregnant women, children or older adults — muscular people often score high with normal body fat. BMR and TDEE are estimates with errors up to roughly ±10%: fine for setting the direction of a calorie deficit, unsuitable for precise dietary control. Any health conclusion belongs with your medical report and your doctor.
Currency, units and amounts: conventions break more often than formulas
Bank apps show bid/ask prices that already include the spread, while these tools use the mid rate — the gap is the bank’s margin, so "not matching" is not an error. Unit conversion trips people up on area (1 m² = 10,000 cm², squared factor) and time (mixed base-60 and base-1000 steps). For money, convert to the smallest unit before comparing, and on invoices and contracts write both numeral and capitalised amounts — when they disagree, the capitalised figure governs.
Date calculations: countdowns, age and due dates
Countdowns use your local time zone and whole days, so they may differ by one day across zones. Age tools report both the standard age and the traditional Chinese age, which counts birth as one and adds a year each Spring Festival — a one- to two-year gap is normal. Due dates follow Naegele’s rule (last period plus 280 days) assuming a regular 28-day cycle; irregular cycles can shift it by over a week, and your clinician’s ultrasound-based dating always wins.
FAQ
Why does the mortgage figure differ from my bank by a few yuan?
Usually rounding conventions, the disbursement date and first-period day counts, or per-day interest accrual. Differences of a few yuan to a few tens are normal; the repayment schedule is authoritative.
Do you store my income or loan amount?
No. Calculations run in the browser: inputs are never uploaded or written to a server, and reloading clears them. There is no account system to store them in.
Can I use the result for tax filing or signing a contract?
No. These tools are for estimating and comparing — use the tax system, your bank’s official calculator or a professional for anything binding.