1. How you actually use the shelf
Start with the most important question: Do you mainly want to lie back, or mainly want to sit up?
If your shelf is for slow mornings, quiet afternoons, and tanning, go reclined.
If your shelf is for conversation, drinks, reading, and family use, go upright.
2. Your available shelf space
A reclined in-pool lounge chair usually needs more usable length. An upright chair often gives you more flexibility on a shorter or tighter ledge.
If your shelf is compact, the wrong chair shape can make the whole space feel crowded fast. And if you are still figuring out how much ledge space you really need for one chair, two chairs, or a full paired setup, it makes sense to check a sizing guide before you buy. See what size tanning ledge you need for pool lounge chairs.
3. The actual water depth on your sun shelf
Before buying any in-pool lounge chair, check the real water depth where the chair will sit.
That matters because sun shelves and tanning ledges are not one-size-fits-all pool features. Residential pool standards specifically account for design variations such as ledges and other special shallow-water features, which is why measuring your own shelf is always smarter than guessing.[1] If you are not sure what depth range makes sense for in-pool seating, read how deep water should be for an in-pool lounge chair.
4. Chair size, not just chair style
Many buyers compare looks first and dimensions second. That is usually where mistakes start.
Even two chairs in the same category can create very different layouts on a sun shelf. A shorter, more upright-style chair may work well on a compact ledge, while a longer reclined chair may need much more front-to-back room to feel right. For a broader fit-first checklist, see how to choose the best pool lounge chairs in water.
5. How much direct sun exposure you want
This is one of the small details many buyers forget.
If you are choosing a reclined chair because you expect to spend longer stretches tanning or relaxing in direct sun, plan for sun protection too. The American Academy of Dermatology recommends a broad-spectrum, water-resistant sunscreen with SPF 30 or higher for outdoor use, with regular reapplication during extended time outside.[2]