Not all mattresses bend the same way. Check your frame type before buying: Folds once lengthwise (the most common type).
Aim for at least 6 inches for comfort. Anything less will feel like sleeping on the floor slats.
Choose a firmer foam that won't "bottom out" when people sit on it for long periods. 3. The "Fold" Factor
Heavier mattresses (like innerspring) stay in place better but are a workout to move or convert. 5. Don’t Forget the Cover