Cell Usage Spreadsheet
Posted on 8 October, 2009So I’ve been keeping a spreadsheet that tracks my usage per month so I can change stuff on my phone’s account ahead of time based off trends calculated from previous months. It predicts what I might use the next month and if it shows that I’ll go over my minutes or messages to the point where it gets expensive, I can bump my plan up a notch so that I avoid some of those outrageous charges (like $75 for 400 messages in ’08 – could have saved $70 by switching to unlimited). So here’s the figures for this month…
Minutes (450 min + 4109 rollover min + 5000 night and weekend (no rollover))
Minutes Predicted: 299 min
Minutes Used: 269 min
Error: 10% (down)
Data (unlimited)
Data Usage Predicted: 269836 kb
Data Usage Used: 136808 kb
Error: 49% (down)
Messages (1500 text + MMS)
Messages Predicted: 1202 messages
Likelihood of exceeding 1500: 45.15%
Messages Used: 1069 messages (1067 text, 2 MMS)
Error: 11% (down)
So let’s analyze this.
I really don’t use the minutes I’m alloted for by AT&T. Almost nobody I know makes calls any more. Most of my calls are to home. If AT&T had a low voice plan (200 min or so) for non-seniors, I would jump on that quick. That or I need to find more people to call. Case in point – since January 2008, the most I have called was 400 minutes in August. I got 50 rollover minutes from that.
Data usage is going down from summer. This is mostly due to the university having wireless everywhere on campus and wireless at the apartment. I rarely, if ever, go to 3G except when in Starkville. The predicted numbers should start falling in the next few months, bringing the 49% error rate down close to 10%.
Messaging is getting more accurate by the month. 11% down is very acceptable when talking about 1k messages.
So the equations aren’t perfect yet – I need to tweak them one more time, but they are fairly accurate based off past months.
