There is a slight disadvantage in this case because the use to date may not represent typical use, but it is probably not significant enough to make a difference. For example, if the printer is supposed to do 5,000 pages of normal printing per toner and you’ve used it for six months. So far, 3,000 pages have printed. If the best price available for toner is $85.00 then divide 3000 by 5000. Multiple the result, 0.6 times $85.00 for a cost to date of $51.00. Start the spreadsheet with either the full cost of toner or the partial cost.
to see the labels and formulas used in the setup. Labels are typed as is. Precede formulas with the equals (=) sign.
Setting up this spreadsheet takes a little time in the beginning, but it is a one-time step. After that, it’s just a matter of updating the sheet when a new toner is put into service. It will pay of in the long run because it provides useful information about your printer use.
Now all you have to do is fill in the date, cumulative pages printed from the printer report, what the last ream of paper cost and the price of the toner. Update the toner and paper cost at each toner change and the current per page cost will appear. Until those numbers are entered, the formula cells will show either #DIV/0! or a negative number—ignore this.
Once you have reliable cost figures, you can decide whether a visit to the local shop is cost effective or not. One caveat: These calculations do not include the wear and tear on your laser printer. With a little more work, this could be factored in by amortizing the cost of the printer over a chosen time, say four years. Even the real cost of the printer (after a tax deduction) could be included for extra precision.
