Bright visual display, not just audio. Additional sensors locate stud edges. No calibration cycle required.
Doesn't work well on materials other than drywall. Some concerns about long-term performance.
Special light draws arrow on targets. Penetrates varying thicknesses of different wall materials. Also has AC wire finding option.
Requires several passes to find stud edges. Prone to false readings caused by electronic interference. Better at finding studs than joists.
Detects center of stud, not just location. Also detects live electrical wiring. Deep scanning mode for thicker or insulated walls.
Slight twists during scan can create false readings. Electronics no better than magnetic scanning techniques. Better at finding AC wires than studs.
Super-strong magnet sticks to stud nails. No batteries or calibration required. Small enough for a tool belt.
Not as versatile as an electronic stud finder. Weak attraction to drywall screws. Does not find center of stud, only metal fasteners.
Basic bubble level also included. Strong magnetic attraction to stud nails, few false readings. Only a simple S sweeping motion required.
Only detects metal nails, not wooden studs. Same effect possible with a strong standard magnet. Does not work with thicker plaster walls.
Whether you're hanging a cabinet, a mirror, or a widescreen TV, knowing where your wall studs are is vital for getting things fixed securely and safely. Fortunately, there are a wide range of stud finding gadgets available to help. No more hit and miss with a hammer or a knuckle. The right tool can find those studs in seconds.
But which is the right tool? Old-school magnetics or modern electronics? BestReviews is here to help. Our combination of workshop testing, expert consultation, and customer research is focused on helping you make the right buying choice.
Our findings are completely independent. Accepting samples from manufacturers might lead to bias, so we buy everything we test using our own money. The stud finders in the product list above are those we recommend. They cover just about all the possible choices, so they offer performance and value to suit every user. If you'd like more detail on how stud finders work, and answers to many of the questions that crop up, please read the following report.
There are two main types of stud finder, magnetic and electronic.
Magnetic stud finders use a very simple concept: the nails that hold studs together are magnetic, and so are dry wall fixings. If your magnetic stud finder sticks to the wall, there’s a good chance there’s a stud there!
Not surprisingly, there are some pretty strong magnets involved. Some are molded into a durable plastic casing, others are left loose. With a fixed magnet, you just push it across the wall until you can feel magnetic attraction. With a loose magnet, you get either an audible "thunk" as the magnet is attracted to the fixing, or there's a visual indicator — generally a bright piece of plastic will pop up.
Often the stud finder incorporates a central groove, or "V," to help you position a nail or screw, or make a pencil mark. A bubble level might also be incorporated.
The main drawback with a magnetic stud detector is that they locate the fixing, not the stud. There's no way to know if the fixing is off center. They're also attracted to any ferrous metal, so it could be a drywall screw – but it might also be steel tube, rebar, or who knows what hiding in the wall.
Electronic stud finders come in a variety of forms, but all work on the same basic principle. Using one or more sensors, they measure changes in the density of the wall (technically, the dielectric constant).
Most need to be placed against a wall for calibration (an area where there is no stud), then as they are moved along the surface they measure the wall and feedback data until a different density is found.
Unlike magnetic stud finders, they're not reliant on magnetism at all, so they find both wood and galvanized steel studs equally well. Results are displayed on an LCD screen, which gives a quick and clear indication of what's going on.
Electronic stud finders are further broken down into two types: edge finders and center finders.
In general, an edge finder has a single sensor that detects a change as it occurs — the edge of a stud. It cannot tell you the size of the stud, so it's a good idea to make a mark, then approach from the other side, to make sure you know the width. You can then mark the center of that stud.
Center finders have multiple sensors, so they can gauge the full width, and indicate the center for you.
Most electronic stud finders do struggle if wall thicknesses are inconsistent, and with lath and plaster walls in particular. "Deep scanning" modes can overcome this to some extent, but it may be necessary to take several readings to get an accurate picture of where studs are.
A third, and relatively recent introduction is the multi-sensor stud finder, also called an instant stud finder. These, as the name suggests, incorporate an array of sensors. They can read a whole wall at once, mapping multiple stud locations in one go. They don't need to be calibrated either. Because these stud finders take multiple readings, they handle irregularities better than edge or center finders. As a result, they're usually more accurate.
Some electronic stud finders can detect live electric (AC) cables. A very useful safety feature.
Some models can detect metals – both ferrous and non-ferrous. A basic model might find the edge of a “stud,” only for it to turn out to be a hidden copper water pipe. An advanced model that identifies the pipe could save you a big plumbing bill!
Most electronic stud finders require a 9 volt battery to operate. Frustratingly, this is often not supplied.
Basic magnetic stud finders can be found for ten bucks or less. Thousands of satisfied customers will tell you they work just fine. They do, but there's no precision. These models will find fixings that are off center, metal pipes, and conduit, without differentiating between the types of objects.
Edge-finding models cost around $25 to $35, and for the money you often get standard and deep scan modes and possibly live AC wire detection. These stud finders work equally well on wooden or metal studs.
For around $50 you can step up to a center finder. Again, it's likely that you'll get depth modes, plus live AC detection. You might also get metal identification – both non-ferrous (like copper pipes) and ferrous (steel conduit, for example).
Wide, multi-sensing models are capable of indicating not just the edges and center of a single stud, but can identify several studs at once, and unusual widths. At anywhere from $50 to $75, a multi-sensing stud finder is very much a pro's tool, but if it's something you use frequently, it's probably worth the investment.
Once you've identified your stud, move away, then come back and “find” it again at a different height. Now find the next stud along. Is it where it's supposed to be? Studs are usually located 16" or 24" apart. What you're trying to do is ensure you've got a stud, and not a random cable or length of pipe.
Some stud finders are surprisingly sensitive to battery charge. If yours was working yesterday, and isn't today, try changing the battery before anything else. One manufacturer told us that nine times out of ten, a weak battery was the problem.
If you're using an edge finder, be sure to find both edges, so you can place your fixing in the center. Never assume the other edge is a set distance away. Maybe it is standard, but maybe the contractor ran out, and used something else, just that once? You never really know what went on when that wall was put up. Better safe than sorry.
Though it's called a “2 x 4” stud, it is unlikely to actually measure 2" x 4". Nominal 2 x 4 lumber is usually 1 1/2" x 3 1/2".
Mounting a TV can be problematic if the bracket doesn't match your stud spacing. It's always best to use studs if you can – they're more secure – but drywall anchors can be used. Ensure they have the correct load capacity, and use plenty. Never think you can get away with using less than recommended.
Standard, pre-cut studs are specified as eight feet tall, but are actually 92 5/8" to allow for top and bottom plates. If your walls are an unusual size, it's not unknown for small sections to have been nailed to standard studs to reach the required height. If you're fixing something within six inches of the ceiling, double check that your stud is where you expect it to be.
Q: What is AC Detection?
A: AC detection (also called AC scan, or other similar names, depending on manufacturer) is an attempt to find cables carrying live current, hidden in your wall. They can provide a useful guide, but caution is always necessary. They seldom register cables more than 11/2 inches below the surface, a distance that can further be reduced by concrete, conduit or other obstacles. As a safety precaution, always turn main power off before drilling into walls.
Q: Some of this technology is very clever, but can't I just use a big old magnet to find studs?
A: You could, but it's a method that's very hit and miss. Using a magnet will find steel nails or screws, but not the actual stud – nor its center. A magnet can't discriminate. It will find any steel object – for instance a steel pipe, or a long-forgotten electrical box.
Q: Do electronic stud finders work with lath and plaster walls?
A: The challenge with lath and plaster is the variety of ways it's made. Even though the surface looks smooth, the underlying structure can be extremely varied. This tends to confuse electric stud finders, which work by finding changes in wall density. To make matters worse, some lath and plaster walls are reinforced with steel mesh, throwing magnetic stud finders out as well. The old-fashioned method is to tap the wall with your knuckle until the sound changes. Unfortunately, this is one occasion when modern methods often aren't any better!
BestReviews wants to be better. Please take our 3-minute survey,
and give us feedback about your visit today.