How long should an iPad hold a charge?

Welcome!

Well, you almost ask a "how high is high" question. There are a lot of variables that affect how long a charge lasts:

iPad model:

Huge variable. Batteries' initial capacity varies wildly with iPad model/generation. Old iPads with less efficient processors often had higher battery capacities than newer iPads with more efficient processors. Examples:

— iPad 1 (2010) 6613 mAh

— iPad 3 (2012) 11487 mAh

— iPad 5 (2017) through iPad 9 (2021) 8827 mAh

— iPad 10 (2022) 7606 mAh

[Ref: data from from the Mactracker database]

And that is just the "regular" iPad. Capacities for the iPad Mini, iPad Air, and iPad Pro will be different.

Battery condition:

Batteries are a wear item. Through normal use they lose capacity and therefore runtime, requiring more frequent charging than when new. Battery age is BIG factor in how long a charge holds.

Environment:

Holding a charge will vary with operating temperature. All batteries are little factories using chemical reactions to convert chemical energy to electrical. Chemical reactions slow as temperatures go down.

User Activity:

Some apps ar more demanding than others. Near the top of the "I'll Drain Your Battery" list are videos. They need more energy to retrieve, decode and display your fav movie or video podcast. Just being connected to a network needs more energy than when wifi is off.

Those are just the tip of the iceberg. If you give us the exact model of your iPad, perhaps one of us with a similar tablet can share their experiences. To accurately ID you iPad model, this Apple support document is quiteuseful:

Identify your iPad model - Apple Support

If you are interesting the using the Mactracker database, open your iPadOS App Store and search by the name. It's usually the first one to pop up.