Optimizing Your Monthly Average Balance Calculation for Standard Chartered Bank
Honestly I am pretty annoyed why UOB and SCB don't calculate the monthly average balance for you but OCBC did it. They definitely have to calculate otherwise how do they pay it. But yet they did not expose that part to you despite having so many resources to do so. I think the reason boils down to the fact that OCBC has the Save bonus element which they need to show to you, otherwise they might get a lot of calls to their call centre to ask about their own monthly average balance.
Whereas for UOB and SCB, they don't have the save bonus element, so they don't need to calculate the monthly average balance for you. And better still, you put in more than $100,000 / $150,000 respectively and they only need to pay some pathetic rate to you.
Due to the fact that interest rates are dropping almost everywhere except for SCB which surprisingly increases the rate since 1 June 2025, I am starting to shift more money to it and try to optimize my monthly average balance to get the best interest out of it.
If you are spending more than a minute trying to key into your excel and calculate the monthly average balance, this tool is for you.
How to calculate monthly average balance
Similar to all other banks, the calculation use the end of day balance and add them up divided by number of days to determine the monthly average balance. However, for the base interest, they use the end of day balance and applied a base rate of 0.05%. Based on my own logic and testing, I am unable to match how they actually calculate the base interest. I can only get close to it but there's a small variance of couple of cents.
In addition, because the bonus interest of salary credit and spend is capped at $100k which I can meet, I also cannot tell from my own data if the calculator is working correctly based on the CSV upload.
Based on my own observation, there are some transfers done during the weekend, although the date stated is the following working day which is Monday, under the description there's "Value Date" indicated. So the logic I use adds them according to the value date to calculate the average daily balance.
How to use the Standard Chartered Bank Monthly Average Balance Calculator Tool
The calculator has some pre-assumptions.
- You need to upload the CSV file from SCB as it is with no amendments.
- You can only download the CSV file when using desktop.
- The default output for the CSV file if you did not toggle will be last 30 days which is safe to calculate.
- The last day of prior month is important because it uses a forward fill logic. eg. If you have no transactions on 1 / 2 July, only have transactions on 3 July, the end of day balance will only be accurate using 30 June 2025. If that data isn't present, it will use 3 July end of day balance and backfill them (the default I assume) but it won't be accurate. So best to upload the CSV file with the last day of prior month.
Conclusion
I also have one for UOB built but hosted on another domain. For the UOB Calculator, I am very confident it works correctly since UOB do show it on their website after the month ended and I can tally them. However for SCB, I don't see any way to verify it or maybe I am missing something.
If you manage to test out the tool, especially for users that didn't meet 100k, please let me know if it works correctly.
Hope you find the calculator tool useful.