The flight time you need (14 CFR 61.109)

Under Part 61, the minimum flight experience for a private pilot certificate with an airplane single-engine rating is in 14 CFR 61.109(a). It's at least 40 hours of flight time, which must include at least 20 hours of flight training from an instructor and 10 hours of solo flight training.

The 20 hours of training must include

• 3 hours of cross-country flight training.
• 3 hours of night flight training, including one cross-country flight of over 100 NM total distance and 10 takeoffs and 10 landings to a full stop (each landing involving a flight in the traffic pattern) at an airport.
• 3 hours of flight training on the control and maneuvering of the airplane solely by reference to instruments.
• 3 hours of flight training to prepare for the practical test, within the preceding 2 calendar months before the test.

The 10 hours of solo must include

• 5 hours of solo cross-country time.
• One solo cross-country of at least 150 NM total distance, with full-stop landings at three points, and one segment of at least 50 NM straight-line distance between the takeoff and landing locations.
• Three takeoffs and three landings to a full stop (each with a flight in the traffic pattern) at an airport with an operating control tower.

What "cross-country" means here

For private pilot training, cross-country time generally means a flight that includes a landing at a point other than where you departed, and that's more than 50 NM straight-line distance from the original point of departure (see the definition in 14 CFR 61.1). A short hop to the next airport over doesn't count toward these requirements.

Minimums aren't averages

40 hours is the legal minimum, not a prediction. Most students take noticeably more, because the checkride standard (the ACS) is what decides when you're done, not the clock. Treat the hours as a checklist to complete along the way.