Estimates of national average duplexing rates are shown below. Estimates of typical duplexing rates found in offices are few and of uncertain quality. The only widely known estimate for U.S. copiers is based on figures produced in 1990 and is shown below. The speed is the rated copies per minute that the copier makes, and the duplexing rate is the fraction of images made on duplexed paper. Printers For printer duplexing, you are probably best off observing any duplexing printers you have and estimating from that.
Most printers don t have a duplexing unit.
Many fax machines take about 20 seconds to send each page, though you can easily time your machine on several faxes to confirm this. The send time depends on the speed of connection and the resolution used. Your phone bill for the fax line may indicate total transmission time, which, divided by the time per sheet, indicate pages sent. You can use the amount of toner or ink bought as an indication of the number of copies made. However, you might use it considerably slower or faster than average, so use such estimates cautiously.