It does not require calibration. Make sure your screen is clean because it's pretty sensitive to fingerprints and other stuff on the screen. What version of the os are you on?
I can't find anything in the settings to adjust touch calibration. I've noticed this because sometimes when I touch a button, it won't respond. Why does it sometimes highlight something you've touched but not actually respond? Also, does anyone else have problems with the browser not responding to touch? Every device I have owned that had a touch screen required calibration, but not the NC and I cannot find any documentation regarding this.
I've had older devices with resistive touch screens that had calibration algorithms built into their firmware, but I've not had a capacitive touch screen device in some years now that requires it or even has the feature at all.
Like most of these modern, high resolution capacative screens, the NC does not have any calibration feature. Usually, when a button doesn't respond, it's not because the screen failed to detect the touch, but the software for that program that interpretes it is locked up or not responding. Sometimes closing that app (eg. browser) and open another, then going back to it may fix it. Or, the unfortunate, but nowadays usual remedy of powering the device off, then re-starting it may clear out the glitch. If it occurs repeatedly with the same app, it is possibly just bad code or implentation in that app.
Even with a clean screen, the calibration is off on my NC. I have to touch the screen a little ABOVE where I intend to touch, because the NC registers my touch a little below the spot I do touch. A capacitive stylus helps on the keyboard, but the stylus does not work with some apps.