Guys dont get confused with account usage.Tvmguy is right.Remember this 1. Bsnl total usage is the consolidated usage2. Bsnl detailed usage is the one which gives info elaborately.3. Billed usage is the previous month usage & unbilled is the current month usage.Now understand this for home 250 plan bsnl charges 90 paise for extra usage. But on the usage table they charge you for your regular usage of 1GB which is free. As a result even if your total download is say 1GB the total Rs. would show for 1GB (1024MB) total amount would be Rs.921But actually you will be billed only Rs.250. So the fact is they calculate Rs. for the free usage which is 1GB which doesnt matter. You shouldnt worry until your bill exceed Rs.921 for home 250 plan.Tvmguy is right. To calculate the total MB used excluding Night Unlimited you cannot see the total data transfer as it includes NU. So look at the Rupees say Rs.1000 which is calculated excluding NU from it you can calculate the amount in MB that you have downloaded by dividing it by .80Let me work it out for you, say you have total traffic of 2000 MB out of which only 1024 MB downloaded in day time. The table under consolidated usage shows you 2048000 KB which equals 2048000/1024= 2000 MB.But the amount in Rupees is calculated by bsnl only for day time i.e for 1024 MB alone. which we eventually need. So the amount may turn up intoas 1024 X .80 = Rs . 819.20 (1MB = 80 paise). Thereby if you wanna know the account usage excluding night unlimited, look for amount in rupees which in the above case may show Rs. 819.20 dividing it by .80 gives the total usage in MB here 1024 MB