Often network folk have to make quick estimates without benefit of calculators, measuring tapes, or other handy things. I was thinking about this the other day, and thought I’d post some of the techniques I use.

- I’m 6′ tall, so my armspan is about 6′. Great for measuring the length of cables
- One big pace is about a meter (or 3′)
- Every megabit per second of bandwidth will transfer about half a Gig of data per hour, at best.
- having a rough idea of the cost of a switch, GBICs, and installation, rough guesses for the cost of data circuits (operational and capital), internet bandwidth costs

Any others?