Door hinges are a piece of door hardware that is not usually noticed until they go wrong. They are vital for keeping both internal and external doors operating correctly, so if you have a broken hinge or a hinge that is in poor condition, it’s a good idea to replace them as soon as possible.
A door hinge has a standard size of 3.5″ in width, 3.5″ in length with a door thickness of 1 ⅜ inch. You can also find many other sizes on the market, including a 3.5-inch hinge, 4-inch hinge, 5-inch hinge, 6-inch hinge, 5-inch commercial hinge, and 6-inch commercial hinge.
Read further to understand the detailed size guide.
Door Hinge Sizes
Hinges, when folded out flat, are exactly square, but when they are in use, they will be folded between the door and the door frame and therefore may look like a rectangular shape.
A door hinge is measured when it is open wide or when it is laid out flat and not yet attached to a door. The measurement is taken from the very edge of one side of the hinge to the other and then from the top edge of the hinge to the bottom.
If your hinges are still fitted to your door, it can be difficult to get an accurate measurement so that you know which hinge size to buy because the space around the door is usually quite tight.
When selecting which hinges you will need, you can actually find this out just by measuring your door, which is a much easier task. The door measurements you will need to take are the width of the door and the thickness of the door.
The height of the door is not important, although you will need this to determine how many hinges you need. Standard hinges for standard-sized internal doors measure 3.5 inches by 3.5 inches; however, if you have non-standard doors or you are measuring for exterior doors or for doors in a commercial space, then this is likely to be different, and you will need a different size of hinge. Always measure your door before buying new hinges.
3.5-inch hinge (Standard Size)
This is the standard size of door hinge for internal doors on residential homes, and it is the most common size of hinge. It measures 3.5 inches wide and 3.5 inches long. This hinge is compatible with doors that are equal to or less than 32 inches wide and which also have a door thickness of 1 ⅜ inch.
4-inch hinge
This hinge is slightly bigger than the standard size hinge, by a half-inch in each direction, giving it a total measurement of 4 inches wide by 4 inches long. It is suitable for doors that are one ⅜ inch thick and which have a width measurement of between 32 and 36 inches. The additional size will give this hinge the strength to cope with the extra weight of a wider than average door.
4.5-inch hinge
The 4.5-inch hinge measures 4.5 inches wide and 4.5 inches long. It can be used on slightly thicker than average doors, with a door thickness of 1 ¾ inch. The width of the door can measure anything up to 36 inches to be compatible with this hinge.
5-inch hinge
This is a larger hinge which is suitable for doors that are both thicker and wider than standard. The hinge will measure 5 inches wide and 5 inches long. It can be used on doors that have a thickness of 1 ¾ inch and which are between 36 and 48 inches wide.
6-inch hinge
This is the largest size of hinge you can expect to find when installing doors or replacing hinges. It is designed to be able to handle the additional weight of a door that is very wide.
This will typically include doors used in disabled toilets and care homes, which are made wider to accommodate wheelchairs. The size of this hinge is 6 inches wide and 6 inches long. It is compatible with doors that have a thickness measurement of 1 ¾ inches and a width measurement of over 48 inches.
5-inch commercial hinge
This is a commercial hinge that is designed specifically for use in commercial applications where doors tend to be thicker and heavier, and therefore the hinge needs to be more heavy-duty to deal with the extra weight.
The 5-inch commercial hinge measures 5 inches wide and 5 inches long, but it differs from a standard hinge because it will be made from thicker metal. This size of hinge can be used on doors that have a thickness of 2 inches, 2 ¼ inches, and 2 ½ inches. The width of the door will need to be less than 42 inches.
6-inch commercial hinge
This is another type of commercial hinge which is extra-large to make it better suited for coping with the additional weight of an extra wide and extra thick door. The hinge measures 6 inches wide and 6 inches long and will be thicker than standard hinges. It is compatible with doors that have a thickness of 2 inches, 2 ¼ inches, or 2 ½ inches. The width of the door can be over 42 inches.
Hinge Placement
The size of the door will dictate the size of the hinges required, as well as how many you need. For doors that are less than 60 inches tall, you will only need two hinges. For doors with a height of between 60 inches and 90 inches, you should use three hinges. For doors that measure between 90 and 120 inches, four hinges will be needed.
In most residential scenarios, three hinges will be needed. American construction standards dictate the placement of these hinges. The top hinge should be fitted 5 inches from the top of the door, and the bottom hinge should be fitted 10 inches from the bottom of the door.
The third and final hinge should be fitted halfway between the top and bottom hinges. This will ensure your door satisfies building code and make for a sturdy and secure door that should operate seamlessly for many years.
