The hollow‑wall anchors that come in the largest diameters are generally heavy‑duty toggle‑style or specialty “plasterboard” anchors that use a relatively large drill hole (often 1/2 in or more) and a large bolt or screw (up to about 3/8 in).

Anchor types and diameters

  • Standard plastic or self‑drilling drywall anchors are usually small, with typical outside diameters around 1/4 in to 5/16 in and matched to #6–#8 screws.
  • Heavy‑duty metal toggle bolts and similar toggle‑style anchors are sized by the bolt diameter , often 1/4 in or 3/8 in, and require significantly larger holes than plastic anchors.

Largest “common” options

  • Conventional toggle bolts in the consumer range go up to about 3/8 in bolt diameter, and require a hole larger than the bolt—commonly around 1/2 in or more.
  • Some modern toggle‑style drywall anchors are sold specifically as “large toggle” anchors and specify hole sizes around 3/8 in for #8 screws, already larger than most plastic anchors.

Specialty heavy‑duty anchors

  • Specialty high‑capacity plasterboard anchors (often European or pro‑grade brands) may be rated for very high loads and use large drill bits or spade bits, again in the 1/2 in range or higher, to accept large screws or bolts.
  • These systems are effectively hollow‑wall anchors but start to overlap with light framing/through‑bolting practice, where the limiting factor is the wall, not the anchor diameter.

Practical takeaway

  • If your goal is “largest diameter” in a normal DIY context, heavy‑duty toggle bolts (up to about 3/8 in bolt size) and large toggle‑style drywall anchors are as big as it gets before you move to framing or structural attachment methods.
  • For very heavy items, anchoring into studs or using a rail system is usually safer than trying to push drywall or hollow‑wall anchors beyond those sizes.

Information gathered from public forums or data available on the internet and portrayed here.