It's about 40.6mm 1.6") which is similar to the nut width on Fender Squier guitars. Most Strat style guitars are closer to 42mm, but if you're thinking of replacing the nut you can buy a standard Strat nut, center it, and sand a little on both edges to make the nut width match the neck size. I did this on a Squier guitar with no issues.
Perfect backup/practice guitar - surprisingly well-made for a low-priced guitar. The neck looks to be solid Maple with a Rosewood fret board and is stain/unfinished....makes it easy to sand the sides of the neck and take out any fret burrs. Having played several low-priced Squier guitars, I'd say this one feels and plays better, which was a nice surprise. Guitar body has a great dark/navy blue paint job with glossy finish. Some things you'll probably want to replace after playing for awhile - the tuning pegs are cheap (expected at this price range), replace the plastic nut with a higher quality one, get rid of/replace the string tees, and Id recommend replacing the stock trem block with a Fender-branded one. All of these items should cost under $100. Guitar is definitely playable out-of-the-box. Good for a beginner because the overall investment is low up-front. Really nice Strat-like guitar for the price! Highly recommend.