Hello,
Thank you for reaching out!
That is correct, mobile carriers usually count your data usage as follows:
Total data usage = data downloaded + data uploaded
So total data is the field to keep an eye on if your current plan is limited.
However, please keep in mind that RMS data consumption reports may not be 100% accurate (depending on the connection quality, update period, etc.), and carrier-provided information would be the best source.
Hope this helped!
Best regards,
DaumantasG