Usable vs gross battery
Usable kWh is what you can actually charge; gross is the full pack size.
Automakers quote battery size in kWh, but EVs reserve a buffer at the top and bottom of the pack for longevity. Usable capacity is what the car lets you access in normal driving.
Gross (or total) capacity includes that protected buffer. Two cars with the same gross rating can have different usable numbers depending on how the pack is managed.
When you enter battery size in the calculator, use the usable figure if you know it — it gives more accurate energy estimates.