The entire content of renormalization is summarized as this, given a calculation, you make it match the interaction at some energy. Assuming that the fix is essentially choosing the "scale" of quantities (say, voltage of the electric field, or how strongly electrons tug on other electrons) you are calculating, you fix that scale by making sure that after including it in your theory now, that your result matches the measured interaction at your chosen energy scale exactly. That is renormalization.

If you do this, you find that you need to choose a scale that "absorbs" the infinities of your calculations (yes, an "infinite" scale). But, the stuff that is not absorbed is a function of energy, and this actually agrees very well with experiment beyond the scale you normalized to.