Comparison HP 121XL CC644HE vs HP 121 CC643HE

Estimated cartridge yield is the number of pages that can be printed without replacing the cartridge. The larger the value, the longer the cartridge will last, the more prints you can make with it. At the same time, it should be noted that we are talking about the approximate number of sheets. This is due to the fact that the resource is usually indicated according to a certain standard, which provides for an average rate of filling the page with ink during printing (about 5%). In fact, fill rate do not always correspond to the standard ones, which is why the actual yield of the cartridge may differ from the claimed one. Nevertheless, this indicator makes it possible to evaluate the stock of ink — both in a separate cartridge and in comparison to several models.