Guide
Why the result can change after FX conversion
Interest is only one part
A higher foreign-currency rate can raise the interest amount, but the final converted result still depends on the exchange rate at maturity
FX is the key variable
If the exchange rate moves against the comparison currency, part of the interest difference can be offset by currency movement
Include conversion costs
Banks quote different buy and sell rates. A round trip between currencies can create a spread cost that changes the result
Sources
Reference bank rates
One representative bank is shown for each currency area. Check the official page before using any rate, or enter your own rate above
Methodology
How the calculator works
Interest estimate
The calculator uses simple interest: principal multiplied by annual rate and term in months divided by 12. It does not compound interest unless the user manually enters a rate that already reflects that product structure.
Currency conversion
The comparison currency is first estimated from the exchange rate entered by the user. At maturity, the comparison amount is converted back to the base currency so the two results can be viewed on the same basis.
Threshold rate
The threshold rate is the exchange rate where the two estimated maturity values are equal. It is a calculation line, not a forecast of where the market will move.
Example
How to read an example result
If a user holds CNY and compares it with a USD deposit, the page first estimates CNY interest, then estimates USD interest after conversion. The result cards show the estimated difference if the exchange rate is unchanged, the threshold rate, and one higher-rate scenario.
For example, if the rate-unchanged card is positive, the comparison-currency estimate is higher under the numbers entered. If the threshold rate is close to the current rate, a small currency move may materially change the final comparison.
Limitations
What is not included
Taxes and bank rules
The estimate does not include withholding tax, account eligibility, minimum balance rules, early-withdrawal penalties or product-specific compounding rules.
Live market changes
Reference rates and exchange rates can change. Users should verify official bank rates and the actual transaction quote before using any number outside this calculator.
FAQ
Common questions before using the calculator
What if I do not know the bank rate?
You can leave the rate field blank. The calculator will use the reference rate for that currency. If your bank app, branch or product page shows a specific rate, enter that number instead
What does the threshold rate mean?
It is the exchange rate where the two calculated outcomes meet. Below that line, the comparison-currency result is lower than the base-currency result. Above it, the comparison-currency result is higher
Why can a higher foreign-currency rate still show a lower result?
Because the final result is not only about interest. It also depends on the exchange rate when the money is converted back to the base currency
Which exchange rate should I enter?
Use the rate you can actually transact at. Bank apps, branches, platforms and time of day can show different rates, so use the quote closest to your intended transaction
Can I leave the bank spread blank?
Yes. If left blank, the calculator does not add a spread cost. If you want a closer estimate, enter an approximate spread and review how much it changes the result
Does this page make the decision for me?
No. It is only a calculator based on the numbers you enter. It does not recommend any currency, bank or deposit product. Check official bank rates, fees, early-withdrawal rules and your own cash-flow needs before using the result outside this page
This calculator is for education and numerical estimation only. It is not investment, tax, legal or financial advice and does not recommend any currency, bank or deposit product. Reference rates shown on this page may not be real-time. Always confirm actual rates with the bank's official website, app or branch. Bank rates, eligibility rules, fees and early-withdrawal terms can change at any time