Fit is the question that decides whether a scooter gets used or sits in the hallway. The size on the spec sheet means little until it meets the narrowest doorway, the tightest corner, and the trunk of the car you will load it into. Measure all three before anyone places an order.
Local option: New Plan Care gives families in the St. Louis area in-home help so a parent can stay home: companionship, help with bathing and dressing, meals, and overnight care. Call (314) 405-0887.
Measure the route Dad will actually use
Walk the path from the bed to the kitchen, the bathroom, and the front door. Measure each doorway at its narrowest point, which is usually the door frame or a trim piece, not the door itself. Note any threshold lip and any corner where the scooter has to turn in one move. Mark these on a rough floor plan so the numbers stay tied to the places they describe.
Compare the turning room to the spec
Look up the scooter's overall length, width, and turning radius in the seller's listing or manual. Compare them to your tightest corner. If the spec turning radius is close to the room you have, expect trouble. Ask the seller for the folded and unfolded dimensions if the unit breaks down, and do not rely on a photo for scale.
Check the car before you check the price
Measure the trunk opening, the usable floor depth, and the height if the scooter loads in a hatch. Check whether the rear seats fold, and whether the battery pack or basket comes off separately. Lift the heaviest piece yourself, or have the person who will load it do so, and decide whether the loading routine works for the household.
Plan the charging spot
Pick the place the scooter will sit overnight, then find an outlet within reach of the charger cord. Check whether the charger can stay plugged in there and whether Dad can reach the controls without stooping. A charger on the floor behind a chair is a route problem, not a detail.
Test the seat and the controls
Have Dad sit in a similar seat and try the steering and brake controls. Check the seat height, armrest clearance on the bed side, and how he gets on and off in the house. Ask the seller to confirm the rated weight capacity in writing and compare it to Dad's weight. Ask whether the seller allows a return if the fit fails in the home, and how that return works.
Write three numbers before the order
Put three measurements on one card: the narrowest doorway, the tightest turn, and the trunk opening. If any of those is within a couple of inches of the scooter spec, go back and check again before you order. The Local Help in St. Louis page is the place to start if you want to ask local providers about fitting or loaner options.