Wall Plug Picker: Which Plug, Drill Bit and Screw?
Not sure which wall plug to use? Pick your wall, from plasterboard to solid brick, aerated block or hollow brick, and what you're hanging. The picker gives you the plug or fixing, the drill bit, how deep to drill and the screw to buy, with a shopping list and a screw and wall plug size chart.
No sign-up required. Free to use, with every rule explained on this page. Last reviewed October 2026.
Pick your plug
Wall Plug Picker
Tell it what the wall is made of and what you're hanging. It gives you the plug or fixing, the drill bit, how deep to drill and the screw to buy.
1 What's the wall?
Tiles on the wall?Not sure what your wall is?
- Knock on it. A hollow, drum-like sound means plasterboard. If it sounds hollow in some places and solid in others, it's plasterboard stuck onto brick or block ("dot and dab").
- Find the frame. On a hollow wall, a magnet or stud finder picks up screws or nails in a vertical line every 40 or 60 cm: that's a stud wall.
- Drill a small test hole (4 or 5 mm) where it won't show, and look at the dust. Red or orange: brick. Grey and slow to drill: concrete. Very light grey, almost white, and the bit sinks in easily: aerated block. If the bit suddenly drops through into nothing: hollow brick.
2 What are you hanging?
A metal bracket or hook plate is 2 to 3 mm; a wooden batten 18 to 25 mm.
What to use
Drill bit
Hole depth
Screw
How to fit it
What you'll need
Plugs and screws include two spares.
Before you drill
- Check for cables and pipes with a detector first. In the UK, cables hidden in a wall should run straight up, down or across from sockets and switches, or within 15 cm of the ceiling or a corner. Pipes can be anywhere, and in older homes and much of Europe cables can be too.
- Hammer action only for brick and concrete. It cracks tiles and crumbles block and hollow brick.
- Hoover the dust out of the hole before the plug goes in, or it won't grip.
Screw and wall plug size chart
The plug size is the drill bit to use. Colours differ between brands, so go by the size printed on the pack. UK screws are also sold by gauge number: No. 8 is about 4 mm across.
| Plug and drill bit | Usual colour | Screw | UK gauge |
|---|
A guide, not a guarantee. How much a fixing holds depends on the wall, the fixing and how well it's put in: loads here are typical figures, so check the fixing maker's rating and the item's own instructions. For anything that could fall on someone, a gas boiler or a heavy wall-hung basin, follow the maker's fixing instructions or get a professional in.
How it works
The wall, the weight, then the size
Three things decide the fixing: what the wall is made of, how much weight each screw carries, and whether the item pulls away from the wall as well as down.
The wall
Solid brick and concrete take an ordinary plastic plug. Plasterboard is hollow, so it needs a fixing that grips behind the board, or a screw into the timber frame. Aerated block is soft and needs a spiral plug, and hollow brick needs a long plug that knots up behind the brick's inner wall.
The weight on each screw
The picker divides the weight by the number of screws. Shelves, TV brackets and wall cabinets count double, because they lever the top screws outwards. In plasterboard, about 15 kg a fixing is the most to rely on; above that the picker sends you to the studs or through to the brick.
The plug and screw size
The plug size is the drill bit size: a 6 mm plug goes in a 6 mm hole. The hole is the plug's length plus 5 mm, and the screw is the plug's length plus the thickness of what you're fixing, plus 5 mm. Colours differ between brands, so go by the size on the pack.
Examples
What to use for common jobs
Everyday jobs and the fixing the picker suggests, for a 3 mm metal bracket on an untiled wall.
Shelves, TV brackets and wall cabinets are counted double because they lever outwards. A wooden batten needs longer screws: enter its thickness in the picker. Loads are typical figures; check the fixing maker's rating.
Tips
Getting a fixing to hold
Most fixings that fail were the right type in the wrong hole. A few habits make the difference.
Drill the right hole
Use hammer action only in brick and concrete: it crumbles aerated block, breaks the inside of hollow brick and cracks tiles. Wrap tape round the bit at the depth you need, keep the drill straight, and hoover the dust out before the plug goes in.
Check what's behind
Use a cable and pipe detector before you drill. In the UK, hidden cables should run straight up, down or across from sockets and switches, or within 15 cm of the ceiling or a corner; pipes can be anywhere, and so can older or non-UK wiring.
Find the studs
On a plasterboard wall, anything heavy is best screwed into the timber frame. Studs usually stand every 40 or 60 cm. A strong magnet finds the screws in them, or screw a batten across two studs and hang the item from that. Measuring up for a new TV or curtains? The TV Size and Curtain Size calculators come first.
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Common questions
Frequently asked questions about wall plugs
Common questions about wall plug sizes, colours, screws and fixing into plasterboard.
What wall plugs should I use for plasterboard?
For light things, up to a few kilos a screw, a self-drill plasterboard plug that screws straight into the board. For mirrors, shelves and curtain poles, a metal cavity anchor, which opens out behind the board and holds about 15 kg each in 12.5 mm plasterboard. For anything heavier, or that pulls away from the wall like a TV bracket, screw into the timber studs instead.
What colour wall plug do I need?
Colours vary between brands, so go by the size printed on the pack. As a rough guide, yellow plugs are usually 5 mm, red 6 mm, brown 7 or 8 mm and blue or grey 10 mm. The size is also the drill bit to use: a 6 mm (red) plug goes in a 6 mm hole and takes a 3.5 to 5 mm screw.
What size drill bit for a red wall plug?
A red plug is usually 6 mm, so use a 6 mm masonry bit, and drill about 5 mm deeper than the plug is long (35 mm for a 30 mm plug). Check the pack: some brands colour their sizes differently.
What size screw goes in a wall plug?
Match the screw's diameter to the plug: 3 to 3.5 mm screws (No. 4 to 6) in a 5 mm plug, 3.5 to 5 mm (No. 6 to 10) in a 6 mm plug, 5 to 6 mm (No. 10 to 12) in an 8 mm plug and 6 to 8 mm in a 10 mm plug. For the length, add the plug's length, the thickness of what you're fixing and about 5 mm.
How do I know if my wall is plasterboard or brick?
Knock on it: plasterboard sounds hollow. If it sounds hollow in some places and solid in others, it's plasterboard stuck onto brick or block, known as dot and dab. If you're still not sure, drill a small test hole where it won't show and look at the dust: red or orange means brick, grey and slow means concrete, and very light grey dust with the bit sinking in easily means aerated block.
How much weight can plasterboard hold?
With the right fixing, about 15 kg per fixing is the most to rely on in 12.5 mm plasterboard, and less if the item levers outwards. Above that, fix into the timber studs behind the board, or onto a batten screwed across two studs. Plasterboard itself gives way well before a good fixing does.
Can I hang things on a ceiling with these fixings?
The picker covers walls only. A ceiling fixing carries the whole weight straight down and fails harder if it lets go, so screw into the ceiling joists for anything heavier than a light, and follow the maker's instructions for ceiling lights, fans and hanging chairs.