Why a range instead of a number
A single figure implies a precision that the underlying evidence does not support. Requirements vary with training, age, total energy intake, and what else is in the diet, and the useful band is wide enough that hitting it approximately is enough.
Aim to land inside the range on most days. Chasing an exact gram total is a good way to make eating tedious without improving the outcome.
Using the per-meal target
The per-meal figure is usually the more actionable half of the result. Most people are close to their target at dinner and well short at breakfast, so the easiest change is normally the first meal of the day rather than the last.
Sources are interchangeable for this purpose. Eggs, dairy, fish, meat, tofu, tempeh, legumes, and protein powder all count towards the same total.
When to ignore the output
If a clinician has given you a protein target, use theirs. If you have kidney disease, are pregnant, or are managing a condition where intake is being monitored, this planner is not the right tool and its assumptions do not apply to you.