In the past, we have seen many mobile operators compete based on price and voice bundle. The amount of voice call minutes were once the major change by some operators charging in per second billing instead of a 30 seconds block or a 1 minute block. That is probably why I have to time my conversation within 1 minute just in case I am charged a second minute when it crosses the 59 second mark.

When it comes to data bundle, most operators do not highlight how they compute it. Is it based on the number of bytes used or is it calculated by blocks of Kilobytes or Megabytes.

For instance, if you ues a instant messenger and send a message which is 26 characters long “ABCD….XYZ”, that should be 26 bytes. If we were to add in overheads, it could be more. let give it say 900 bytes (which is a lot). So total is still below 1024 bytes (1 KB).

Some operators count this as 926 bytes, while some will calculate it as 1024 bytes (1 KB) if they round it up to the closest 1 KB. You might say, that is fine. Something you might have overlooked is that some operators calculated in blocks of 10 KB, 100 KB and 1 MB.

In this case, when you use instant messaging app like WhatsApp and send short messages or pictures, it is considered as 10 KB or 100KB or even 1 MB. Imagine if you send a single character and it sends it as a 1 MB, your data usage will spike up a lot since all the small packets are “upsized” to 1 MB.

I doubt you only use the data bundle just for instant messaging. Watching youtube might be one of the common things you do. This might have lesser impact as video streams are generally larger, so the difference wouldn’t be that apparent.

* Information is found on respective operator’s website T&C or FAQ. The rest of the information are from media enquiries.

To understand this issue, you can try to log your data usage using a third party app and compare it with the data logged by your provider and see the difference. If the operator is using per byte or per 1 KB block, the readings should be very close.

Here is a chart we prepared for the various operators and their block size employed for their data calculation. The larger the block size, the impact would be greater for those who smaller blocks of texts and images.

So, the next time when you pick an operator, you should factor in all and start monitoring your data usage with your phone’s built in tracker vs operators’s app and see for yourself the difference.

By Harry