When should you replace door hinges?

When the knuckle has play, the leaves are bent, or the pin is so corroded it won't slide out without a fight. Those are the signs that no amount of WD-40 or screw-tightening will fix. Schlage's buying guide puts the typical lifespan of a residential hinge at 10 to 15 years -- shorter on bathroom doors where humidity eats the pin. Below is how to tell when your hinges are done, how to buy the right replacements, and how to swap them without pulling the door off the frame.

How do you know when door hinges need replacing?

You know door hinges need replacing when the wiggle test fails. Grab the door near the top hinge and try to move it toward and away from the frame -- if there is play, the knuckle barrel inside the hinge has worn down and the pin sits loose. No amount of screw-tightening or lubrication fixes a worn knuckle. It is a mechanical failure of the hinge itself (Schlage, wikiHow).

Other signs to watch for: hinge leaves that are visibly bent (hold a straightedge across the plate to check), a pin surface that feels rough or pitted when you pull it out (corrosion is especially common on bathroom doors), or two or more stripped screw holes on the same hinge that prevent the plate from sitting flat (DoorCorner, Schlage).

Schlage estimates a standard residential hinge lasts 10 to 15 years with normal use. Exterior doors and high-traffic interior doors wear faster, and bathroom doors are especially prone to corrosion from the humidity. If the original hinges were plain-bearing steel and the door weighs more than 50 pounds, DK Hardware recommends upgrading to ball-bearing hinges when you replace them -- ball bearings reduce friction and make heavy doors noticeably smoother to open and close.

What size hinges do interior and exterior doors use?

Interior doors use 3.5-inch butt hinges and exterior doors use 4-inch hinges. This sizing rule is consistent across every source -- DK Hardware, Schlage, Lowe's, DoorCorner, and Angi all confirm the same standard.

The measurement refers to the hinge height (when closed). Standard interior doors are 1-3/8 inches thick; exterior doors are 1-3/4 inches thick (Schlage, DK Hardware). DK Hardware's size chart adds a weight factor: doors under 50 pounds work fine with plain-bearing hinges, doors between 50 and 75 pounds should get ball-bearing hinges, and doors over 75 pounds need 4.5-inch ball-bearing hinges.

How do you match the corner radius on a replacement hinge?

You match the corner radius on a replacement hinge by using the coin test. Hold a dime against the corner of your existing hinge -- if the curve matches, the radius is 1/4 inch. A quarter matches 5/8-inch radius. A right angle with no curve means square corners. Schlage, DoorCorner, and DK Hardware all describe this same method.

The corner radius matters because the mortise (the recess cut into the door edge and jamb) was cut to match the original hinge shape. A square hinge won't sit properly in a rounded mortise, and vice versa. Getting this wrong means the hinge won't seat flush, which throws off the door's alignment.

While you're at the hardware store, match the finish to the rest of the door hardware too. The most common finishes for residential hinges are satin nickel, matte black, oil-rubbed bronze, aged bronze, and satin brass, according to Schlage.

How many hinges does a door need?

A door needs one hinge for every 30 inches of height. A standard 80-inch interior door requires three hinges, which is what most homes built in the last 40 years have installed, according to DoorCorner. Doors shorter than 60 inches use two. Doors between 90 and 120 inches need four. This applies to double-height entries and French doors alike (DK Hardware, Lowe's).

If you're working on an older home where the door has only two hinges and keeps sagging, adding a third in the middle often works better than just replacing the existing pair. The added support distributes the door's weight more evenly and prevents the new hinges from wearing prematurely under excess load.

Can you replace door hinges without removing the door?

You can replace door hinges without removing the door, and this is the method most people should use. Close the door and replace one hinge at a time. The remaining hinges hold the door in position while you swap each one, keeping the alignment intact and eliminating heavy lifting. DoorCorner and wikiHow both recommend this approach.

Start with the bottom hinge. Remove all the screws from both leaves -- door side and frame side -- and lift the old hinge out. Set the new hinge in the same mortise, pre-drill pilot holes if the old ones are worn, and drive the screws. Frame side first, so the door hangs properly, then the door side. Move to the middle hinge, then the top. The whole process takes 10 to 20 minutes per door (DoorCorner).

Angi's expert reviewer Robert Tschudi adds a pro tip: for heavier doors, upgrade at least one screw per hinge to a longer 2-to-3-inch screw that reaches the wall stud behind the jamb. Standard 1-inch screws only grip the jamb wood, which can loosen over time under the door's weight. The longer screw anchors each hinge into the structural framing behind the jamb.

When tapping the pin back in, go gently. Angi notes that forcing the pin down too aggressively can cause squeaking. If it resists, pull it back out and apply a drop of silicone lubricant or graphite powder before trying again.

Do you need to pre-drill pilot holes?

You need to pre-drill pilot holes every time you replace hinges. Pre-drilling prevents the wood from splitting and keeps each screw aligned so it enters straight. Use a drill bit slightly thinner than the screw shaft (Angi, Family Handyman, This Old House). Family Handyman recommends a self-centering drill bit, which seats itself in the countersink of the hinge leaf's screw hole and drills perfectly centered every time.

This matters most with brass screws, which are softer than steel. Brass screws can snap under torque if they hit resistance from unsplit wood (The Spruce notes this in their sticking door guide, and Angi confirms it). Pre-drilling eliminates that risk.

What if the mortise doesn't fit the new hinge?

If the mortise doesn't fit the new hinge because the replacement is a different size, you need to cut a new mortise. The traditional method uses a chisel: score the hinge outline with a utility knife, make closely spaced cuts across the area to the depth of the hinge leaf, then hold the chisel at a low angle and shave the waste out. A utility knife is more accurate than a pencil for scoring, according to This Old House. The chisel method works but takes patience. If you are swapping hinges on multiple doors, Family Handyman's Joe Cruz recommends a router with a flush-cut bearing bit and a hinge template instead -- set the bit depth to the template thickness plus the hinge leaf, test on a scrap piece first, and you get a perfectly clean mortise in one pass.

If a mortise ends up too deep, shim it with a thin piece of cardboard behind the hinge leaf. A cereal box is about 1/16 inch thick, which is usually enough to bring the hinge back to flush (wikiHow, This Old House). Stack two layers for more severe depth errors. If the mortise is too shallow, the hinge leaf will sit proud of the surface and the door won't close properly -- pare away a bit more with the chisel until the leaf sits flush.

What are the most common mistakes when replacing hinges?

The most common mistakes when replacing hinges are buying the wrong size or corner radius, skipping pilot holes, and over-tightening screws. The coin test prevents the sizing error entirely. Measure the old hinge before ordering -- never guess (DK Hardware, Schlage, DoorCorner).

Skipping pilot holes leads to split wood, wandering screws, and stripped holes. Family Handyman recommends a self-centering drill bit, which seats itself in the countersink of the hinge leaf's screw hole and drills perfectly aligned every time. This is especially important with brass screws, which are softer than steel and can snap under torque if they hit unsplit wood (Angi).

Over-tightening is the other quiet killer. Once the screw head is flush with the hinge leaf, stop. Driving it further crushes wood fibers around the hole and weakens the grip, making the screw more likely to strip under the door's daily load (Family Handyman, DoorCorner).

If your hinges have been squeaking or making noise, the replacement process is the perfect time to clean the mortise and check for stripped holes before installing new hardware.