This question comes up in almost every parenting conversation eventually, and most answers land on a specific number — an hour, two hours, forty-five minutes. The number itself isn't really the useful part. What actually matters is what's happening during that time on the screen, and what it's replacing.
An hour spent passively watching cartoons that autoplay one after another is very different from twenty minutes spent actively answering questions, repeating words out loud, and getting feedback. The first is closer to background noise; the second is closer to a real lesson. If you're going to allow screen time at all, the second kind is worth prioritizing.
A useful way to think about it: screen time that replaces outdoor play, conversation with family, or sleep is worth being cautious about. Screen time that fills in a genuinely idle stretch — waiting at a clinic, a car ride, a quiet afternoon — is a much lower-stakes trade-off, especially if the content is actually educational rather than pure entertainment.
One thing that tends to go wrong with screen time for young children is that it has no natural stopping point — one video leads to the next, and a session that was meant to be ten minutes turns into an hour because there was never a clear "this is done" moment. Content built around short, complete lessons (a topic, then a small quiz, then done) naturally caps itself in a way endless video feeds don't.
Most pediatric guidance for this age group lands somewhere around an hour a day of quality screen content as a reasonable ceiling, with quality mattering more than the exact number. If your child is getting outdoor play, enough sleep, and regular conversation, a bit of flexibility on any given day isn't something to worry over.
If you're going to give your child screen time either way, it's worth spending five minutes checking what's actually on the other end of it. That one decision matters more than the clock.