## September 16th, 2001

### Am I missing something?

Okies, I know somebody here can help me.

I'm trying to figure out the cost/KB for a T1 line that moves 1.544 megabits/second, and costs \$18,000/year.

These are my calculations-- they appear to be wrong.

What am I missing?

The facts:
1Byte = 8Bits
Kb=1024 bits
KB=1024 bytes
Mb=1,000,000 bits (why they made that one different, I don't know)
MB=1024 KB, or 1,048,576 bytes
Cost/year = \$18,000
Rate/second = 1.544 Mb
seconds/year = 31,536,000

The figures:

Figure-- cost per KB

1.544 Mb/s = 1,544,000 bits/s

1,544,000 b/s / 8 = 193,000 Bytes/s

193,000 B/s / 1024 = 188.4765625 KB/s

188.4765625 KB/s * 31,536,000 seconds = 5943796875 KB/y

18,000 (cost/yr) / 5943796875 (KB/y) =

3.02836728416968320439113256204604e-6

Or, alternately,

Cost per second:
18,000 / 31,536,000 = 5.70776255707762557077625570776256e-4

Cost/s / KB/s = 3.02836728416968320439113256204604e-6

Thanks for your kind indulgence ^_^
• Current Music
Orbital - Doctor?

### Harmonic Reprise

The facts:
1 Byte = 8 bits
Kb=1024 bits
KB=1024 bytes
Mb=1,000,000 bits (why they made that one different, I don't know)
MB=1024 KB, or 1,048,576 bytes
Cost/year = \$18,000
Rate/second = 1.544 Mb
seconds/year = 31,536,000 (for a non-leap year)
seconds/year = 31,556,952 (taking leap years into account)

The figures:
Figure-- cost per KB

1.544 Mb/s = 1544000 bits/s

1,544,000 b/s / 8 = 193000 Bytes/s

193,000 B/s / 1024 = 188.4765625 KB/s

188.4765625 KB/s * 31536000 seconds = 5943796875 KB/y (for a non-leap year)

188.4765625 KB/s * 31556952 seconds = 5947745835.9375 KB/y (taking leap years into account)

18,000 (cost/yr) / 5943796875 (KB/y) =
3.02836728416968320439113256204604e-6 (for a non-leap year)
3.02635662257797044320626264782112e-6 (taking leap years into account)

Cost per Kilobyte:
\$3.02837e-6 (for a non-leap year)
\$3.02636e-6 (taking leap years into account)

Or, alternately,

Cost per second:
18000 / 31536000 = 5.70776255707762557077625570776256e-4
18000 / 31556952 = 5.70397293122605757362117862333473e-4

Cost/s / KB/s = \$3.02836728416968320439113256204604e-6 (for a non-leap year)
Cost/s / KB/s = \$3.02635662257797044320626264782112e-6 (taking leap years into account)

--------------------

's calculations:
(My results achieved by not rounding numbers expressed on lines beginning with "***")

given:
r=1.544Mb/s
c=18,000\$/y

1.544Mb/s * 31556952s/y = 4.872*10^7 Mb/y
*** 48723933.888

1/(4.872x10^7 Mb/y) = 2.052*10^-8 y/Mb
*** 2.05237943696965226454417768542556e-8

2.052*10^-8 y/Mb * 18,000 \$/y = 3.694*10^-4 \$/Mb = .0369 cents/Mb
*** 3.69428298654537407617951983376601e-4

.0369 cents per Mb.

1Mb=122.0703125KB

.0369 cents/MB * 1Mb/122.0703125KB= 3.022*10^-4 cents/KB
*** 3.02635662257797044320626264782112e-6

3.022 * 10^-4 cents per KB
*** \$3.02635662257797044320626264782112 * 10^-6 per KB

-------------------

Woot-- perhaps my calculations weren't wrong after all. ^_^

Thanks, ropy! Anybody else wanna try?
• Current Music
Supertramp - The Logical Song