Finance & Property · How to use
Personal Loan Calculator
Follow the steps to enter your numbers and check the limits.
Updated 2026-10-25 · ThinkVault Tools
Get started in three steps
- 1
Step 1
Prepare your amounts, terms and applicable rates or prices.
- 2
Step 2
Open the tool, check the units and compare scenarios.
- 3
Step 3
Read the results and notes. Check official documents and sources before deciding.
Method and common questions
APR vs flat rate
The annual percentage rate (APR) expresses interest and some fees as a yearly cost of borrowing, which makes loans comparable.
A flat rate charges interest on the original principal for the whole term. Even as the balance falls, interest is still based on the original amount, so a low flat rate is not equivalent to the same APR.
The two formulas
- APR mode: a fixed level payment from the monthly rate, split each month into interest and principal.
- Flat mode: total interest = principal × annual flat rate × years; payment = (principal + total interest) ÷ number of payments.
Example: borrowing $300,000 for three years
With the same 6.5%, APR mode gives a payment of about $9,169 and flat mode about $9,958. Flat-rate interest stays on the original $300,000, while APR interest falls with the balance. When reading bank adverts, check whether the figure is a flat rate, monthly flat rate or APR.
Why early settlement needs the contract
Some loans charge an early-settlement fee and refund unearned interest using a method set in the contract, such as the Rule of 78. Flat mode therefore shows no guaranteed saving; extra repayments in APR mode are a mathematical scenario.
What to compare before applying
- APR, total repayment and monthly payment.
- Whether handling fees and cash rebates are included in the APR.
- Late fees, early-settlement fees and the interest-rebate method.
- A longer term lowers the payment but usually raises total interest.
FAQ
- Is the lowest flat rate always cheapest?
- Not necessarily. Compare APR, fees, term and total repayment together.
- Do extra repayments always shorten the term?
- It depends on the contract. Some lenders do not accept monthly extra repayments or treat them as prepayment rather than reducing principal.
Method
APR is effective annually: monthly rate = (1 + APR/100)^(1/12) − 1, with equal month-end repayments. Flat interest = original principal × annual flat rate × years. Solve monthly cash flows for m, then APR = ((1+m)^12 − 1) × 100%. No extra fees or rebates are assumed; lender payment rounding and charges can change the APR.
HKMA — Annualised percentage rateLast checked: 2026-10-24
Before you begin
Tax, lending, holiday and protection rules vary by place and date. Check current local rules and provider terms. Results are estimates.