I am looking for a calculation that explains revenue growth net of inflation impact. For example revenue grew 5% year over year, but inflation was 3%. Does this mean that real revenue grow was only 2%? How do I calculate the real revenue growth?

For most practical purposes your method will get you close. The actual relationship between the nominal rate n, the inflation rate i, and the real rate r is...



Given any two of those you can easily solve for the third.

You can see then that in the context of a nominal growth of 5% and an inflation rate of 3%, the real growth over that period is 1.9417... %. Close to 2%, but not quite.

But in casual conversation, when rates are within their usual ranges, a lot of people use the simpler (albeit slightly inaccurate) relationship you used; namely r = n - i.