It can vary a lot depending on your playing style. If you rush through, it might take around 20-30 hours. But if you take your time and explore everything, it could be 50 hours or more.
The time to finish GTA story mode really depends. On average, for a moderately paced player, it could be around 30-40 hours. This assumes you're doing the main missions and some side activities. But if you're a completionist and want to do every little thing, it could stretch way beyond that.
Finishing the GTA story mode can take anywhere from 25 to 50+ hours. It depends on how much you focus on the main plot versus getting sidetracked with side quests, exploring the open world, and messing around. Some players finish quicker, while others take their sweet time to soak it all in.