Wall anchor sizes: screw gauge to anchor to drill bit (drywall and hollow wall)

This page is the size reference for drywall and hollow-wall anchors: ribbed plastic expansion sleeves, self-drilling anchors of the E-Z Ancor type, molly bolts (hollow-wall sleeves), spring-wing toggle bolts, and strap toggles of the TOGGLER SnapToggle type. The chain it untangles is screw gauge, to anchor, to drill bit: an #8 screw does not take an #8-sized hole, a 1/4 in toggle bolt does not take a 1/4 in hole, and the single most common installation failure, the spinning anchor, comes from sizing the hole wrong in a specific, avoidable way. Every table row carries at least two independent sources, and where credible sources disagree, both numbers are printed and named. For wedge, sleeve, and Tapcon concrete anchors, the drill bit chart lives on a separate page: concrete anchor drill bit sizes. That page owns masonry; this page owns everything that grips drywall or opens up inside a hollow wall.

Which anchor page you need

The split is by base material, not by the word anchor. If the wall is gypsum board, plaster over a cavity, paneling, or hollow core, the anchor has to grip a soft facing or expand into a void, and its size chart is here. If the base is solid concrete, brick, or block, the anchor expands against stone and the sizing rules are different: wedge and inch sleeve anchors take a bit equal to the nominal diameter, Tapcon screws take one size smaller, per the manufacturer tables on the concrete anchor bit size chart. The two families never share a row on either page. One border case belongs there, not here: steel hollow-wall sleeves for masonry are still concrete-page territory, and toggle bolts in hollow concrete block reuse the hole sizes in the toggle table below because the wings open in the block's void, a use the Eugene Fastener toggle guide covers [6].

The master chart: screw gauge, anchor, drill bit, capacity

Common wall anchor sizes in one table. Capacity values are ultimate or nominal manufacturer ratings in 1/2 in drywall unless noted; treat them as comparison numbers, not working loads, because both TOGGLER and Eugene Fastener recommend dividing by four for a safe working load [4][7]. Where sources disagree on a bit size, the disagreement is printed in the row, because with unstandardized plastic anchors the disagreement is real information.

Row sources

1. ITW Buildex, E-Z Ancor drywall anchor selection chart, ITW 6400 data sheet (E-Z Mini, E-Z Ancor, Twist-N-Lock, E-Z Toggle rows; screw sizes and max fixture thickness), via the Orgill product document library.
2. ITW Buildex, drywall anchors product table (part numbers 5000900 through 5061902: head diameters 0.400 to 0.603 in, lengths 1.200 to 2.500 in, screw sizes), itwbuildex.com.
3. ITW Buildex Canada, E-Z Drywall Anchors product page: up to 100 lb in shear, 150 lb E-Z Toggle cap, per-job-not-per-anchor warning, no ceiling and no TV warnings, weight table by gypsum thickness, buildex.ca.
4. TOGGLER, SNAPTOGGLE Anchors technical bulletin: drill diameters, ultimate tensile and shear values, grip ranges, and the recommendation to use 1/4 of ultimate test load.
5. TOGGLER, SNAPTOGGLE Heavy-Duty Toggle Bolt product sheet (toggler.com): wing-toggle comparison claim that a 1/4 in wing toggle requires a 3/4 in hole; BA and BB 1/2 in hole listings.
6. Eugene Fastener, Toggle Bolt Drill Bit and Hole Size Chart (wing toggle holes 3/8 to 1 in; SnapToggle table BA through BD with holes and static loads), eugenefast.com.
7. Eugene Fastener, How to Install Toggle Bolts: wing toggle capacities 30 to 225 lb by bolt size in 1/2 in drywall, 4:1 safety factor recommendation, eugenefast.com.
8. Albany County Fasteners, Anchoring Products Guide: anchor type capacities (plastic 10 to 25 lb, self-drilling 25 to 50 lb, molly 25 to 50 lb), toggle wing hole sizes (#6-32 3/8 in through 1/2-13 1-1/4 in), add-to-screw-length column.
9. Hillman 370009 hollow wall anchor specifications (1/8 in diameter, 5/16 in drill size, 50 lb capacity) and the 41306 3/16 in 70 lb listing, via McCoy's Building Supply product pages.
10. Hillman 41304 hollow wall anchor listing: 3/16 in diameter, required drill hole 3/8 in, via Amazon product data.
11. L.H. Dottie WG14L 1/4 in steel wall grip anchor: drill size 1/2 in, grip range 5/8 to 1-3/16 in, via Graybar product specifications.
12. MacDonald Industrial Supply, Hollow Wall Anchor (Molly Bolt) size table: 1/8 in to 1/4 in across XSR/SR/LR/XLR reaches with hole sizes 5/16, 1/4, 3/8, and 1/2 in.
13. Value Fastener, steel hollow wall anchor specification sheet PDF: 1/8 in extra short (5/16 in hole, 6-32 screw) and 1/4 in short/long/extra long (1/2 in hole, 1/4-20 screws).
14. Bolt Depot, 1/4 in XLR hollow wall anchor product data: hole size 1/2 in, grip range 1-1/4 to 1-3/4 in.
15. DGFloors, What Size Drill Bit for Drywall Anchor: ribbed plastic 3/16, 1/4, 5/16 in classes; molly 1/8 in on 5/16 bit and 3/16 in on 3/8 bit; E-Z Ancor types need no bit.
16. TrueTips, plastic screw anchor guide and wall anchor sizes guide: #6 on 3/16, #8 on 1/4, #10 on 5/16, #12 on 3/8; spinning anchor failure; color tiers #4-6, #8-10, #12-14.
17. DecorDash, drill bit size for wall anchor guide: #4-6 on 3/16 in, #10-12 on 1/4 in; match bit to anchor shank; visual comparison method.
18. SOS Metal Products 2026 Industrial MRO Catalog: ribbed plastic anchor line (4-6-8 on 3/16 yellow, 8-10-12 on 1/4 blue, 12-14-16 on 5/16 green) and Rawl plug line with screw ranges.
19. Austin Gallery, Drywall Anchor Weight Chart 2026: plastic 15 to 25 lb, self-drilling plastic 25 to 50 lb, Stud Solver and Twist-N-Lock entries, toggle and SnapToggle 100 to 265 lb, by drywall thickness.
20. Toolkit Reviews, wall anchor plug guide: UK color convention (yellow 4-8, red 6-10, brown 10-14, blue 14-18 gauge screws).
21. Toksomike House, toggle bolt load guide: 1/2 in toggle bolt 1-1/4 in hole; 1/8 in toggle capacity by drywall thickness (27 lb in 3/8 in, 31 lb in 1/2 in, 55 lb in 3/4 in board).
22. Bridge Fasteners, TOGGLER SNAPTOGGLE BC 3/8-16 listing: 3/4 in drilled hole, 275 lb ultimate tensile in 1/2 in drywall.
23. TrueTips, What Size Toggle Bolt guide: 1/8 in about 30 lb, 3/16 in 40 to 50 lb, 1/4 in 70 to 90 lb in 1/2 in drywall; 2x selection rule.
24. Zack Electronics and Opentip, TOGGLER SNAPTOGGLE BB listings: 265 lb in 1/2 in drywall, 356 lb in 5/8 in, 1/2 in hole, 3/8 to 3-5/8 in grip range.
25. Eugene Fastener, Molly Bolt vs Toggle Bolt: molly capacities 30 to about 100 lb, wing toggle 1/4 in about 80 lb and 3/8 in about 135 lb, hole-size principles for both types.

Divergences disclosed, not averaged: the #10 and #12 plastic anchor bit sizes (TrueTips vs DecorDash and SOS Metal), the 1/4 in wing toggle hole (5/8 in vs TOGGLER's 3/4 in claim), the 5/16 in wing toggle hole (3/4 vs 7/8 in), the 1/2 in wing toggle hole (1 vs 1-1/4 in), and the SnapToggle BE/BC/BD holes and loads (TOGGLER bulletin vs Eugene Fastener's table). Also: MacDonald's 1/8 in SR/LR/XLR mollies take a 1/4 in hole while its extra-short-reach 1/8 in and Hillman's 1/8 in take 5/16 in, so check the sleeve, not just the diameter. No source publishes mm equivalents for these inch anchor series, so no mm column is shown; converting would manufacture a spec.

Plastic anchor color codes, and why to not fully trust them

The color of a ribbed plastic wall anchor encodes its screw gauge range in the common US convention, loosely. Two independent anchor lines and two independent guides agree on the tiers, and a fifth source shows the whole scheme is brand-relative.

The caveat is the UK Rawl plug scheme, which uses the same four colors for different gauges: yellow for 4 to 8, red for 6 to 10, brown for 10 to 14, blue for 14 to 18 [20]. Color coding varies by brand [16]; the SOS Metal Rawl line itself codes a 6-8 x 3/4 plug blue on a 3/16 drill, and a 14-16 plug green on 5/16 [18]. If the anchor came out of a mixed jar with no packaging, ignore the color and match the drill bit to the shank outside diameter [15][17].

Toggle bolt sizes: the wing toggle table

A wing toggle is sized by its machine bolt diameter, but the hole is sized by the folded wings, which are two to three times wider than the bolt [6][8]. That is why a 1/4 in toggle needs a 5/8 in hole: the bolt threads into the wing nut, and the holding power comes from the wings clamping the back face of the wall, not from anything in the hole itself [6]. Capacities below are static ultimate values in 1/2 in drywall; both the Eugene Fastener guide and TOGGLER's bulletin say to divide by four for working load [7][4], and capacity drops sharply in 3/8 in board and rises about 10 to 15 percent in 5/8 in board [7][21].

Plastic spring toggles follow the wing toggle hole sizes at the small end: 1/8 in on a 3/8 in hole, 3/16 in on a 1/2 in hole, per the Eugene Fastener chart, with plastic toggle capacities far below the metal wing numbers (20 to 50 lb) [6][7].

Strap toggles: SnapToggle sizes and loads

A strap toggle keeps a metal channel on plastic straps: you slide the channel through the hole edge-on, ratchet it flat behind the wall, snap the straps off, then run the bolt. The channel stays put when the bolt comes out, which makes it the reusable heavy-duty option [4][6]. TOGGLER's own bulletin is the primary source for holes and loads; Eugene Fastener's independently published table agrees on BA and BB and differs on the larger sizes, so both are printed [4][6].

Grip range for the standard BA through BD codes is 3/8 to 3-5/8 in of wall thickness, and the minimum bolt length equals fixture thickness plus wall thickness plus 1/2 in [4][24]. In 5/8 in drywall the BB rises from 265 to 356 lb ultimate [4][24]. The bulletin's own working-load recommendation is one quarter of ultimate [4], which is the 4:1 safety factor the Eugene Fastener guide also states [7].

Molly bolt sizes: the hollow-wall sleeve table

A molly bolt (hollow-wall anchor, wall grip) is a metal sleeve with a machine screw through its center; tightening collapses the sleeve into legs that splay against the back of the wall [25]. The hole matches the sleeve outside diameter, which is larger than the screw: 5/16 in hole for a 1/8 in molly, 3/8 in for 3/16 in, 1/2 in for 1/4 in [9][15]. Reaches (extra short through extra long) exist to match wall thickness, not load.

Capacities: Hillman rates its 1/8 in at 50 lb and its 3/16 in at 70 lb [9]; the independent class rating for mollies is 25 to 50 lb, with heavy long-reach versions reaching about 100 lb [8][25]. The screw can be removed and reinserted without losing the anchor, which is the molly's main advantage over a wing toggle [25][8].

Self-drilling anchors: sizes without a drill

Self-drilling drywall anchors of the E-Z Ancor type screw straight into gypsum board with a #2 Phillips or square driver: no hole, no bit, nothing to size [1][3]. What is sized instead is the screw and the fixture thickness. The ITW selection chart pairs the Mini and Mini Twist-N-Lock with a #6 screw, the standard zinc E-Z Ancor with #6, #7, or #8, the Twist-N-Lock and Stud Solver with #8, all at 3/4 in maximum fixture thickness except the E-Z Toggle at 1/2 in [1][2]. The ITW product table carries the physical envelope: head diameters 0.400 to 0.603 in and lengths 1.200 to 2.500 in across the line [2].

Loads: ITW advertises up to 100 lb in shear and a 150 lb holding cap for the E-Z Toggle, then undercuts its own numbers with two warnings worth quoting: the rating is per job, not per anchor, so two 75 lb anchors do not hold 150 lb, and these anchors are not for ceilings or televisions [3]. Independent guides class the type lower, 25 to 50 lb for plastic-bodied self-drillers and 40 to 75 lb for the metal threaded type [8][19]. The Stud Solver variant keeps threading if it hits a wood stud behind the drywall, which is its whole point [3][19].

Match the bit to the anchor shank, not the screw

Every expansion-style anchor in this page is sized the same way: measure or read the anchor's shank outside diameter and drill exactly that [15][17]. The screw gauge is only a label for what fits inside. Toggles invert the rule on purpose: the hole clears the folded wings, not any part that grips, because a toggle holds from the back face of the wall [6][8].

The failure mode of a too-large hole is the spinning anchor: the screw turns, the anchor has no friction against an oversize hole, nothing expands, and the whole assembly laps the wall [16][15]. TrueTips and DGFloors put the tolerance at a fraction of a millimeter before grip is lost, and DGFloors' practical rule is the carpenter's method: hold candidate bits in front of the anchor body until one hides the shank exactly below the collar, and if you land between two sizes, drill the smaller hole first [15][17]. A too-tight anchor can be tapped in; a too-loose hole means starting over in a different spot with a bigger anchor [15].

Two more hole rules travel with the territory. Drill drywall in rotary mode with a standard twist bit, never hammer, because percussion crumbles the gypsum around the hole [6][15]. And drill into plaster one bit size smaller than nominal, since plaster enlarges the hole itself as the bit wobbles [17][6].

Screw length and the 4:1 safety factor

Screw length is additive. For a toggle, Albany County's chart adds a fixed allowance to wall plus fixture: 1-1/4 in for a 1/4-20, 1-3/4 in for a 3/8-16, 2-3/4 in for a 1/2-13, because the wings need that much bolt behind the wall to open and seat [8]. TOGGLER states the same rule as a formula for strap toggles: bolt length equals fixture thickness plus wall thickness plus 1/2 in [4][24]. For expansion anchors the classic rule is anchor length plus fixture thickness, printed verbatim in the SOS Metal Rawl plug listing [18] and echoed for mollies by the reach-variant system, where the grip range must cover the wall thickness [12][11].

On loads, two independent sources state the same guideline: divide the ultimate rating by four. TOGGLER's bulletin says industry standards recommend 1/4 of ultimate test load [4]; the Eugene Fastener guides say apply a 4:1 safety factor for design loads [7]. That is a guideline, not a code requirement: Albany County tells readers to use anchors rated 2 to 3x the expected weight instead [8], and TrueTips' toggle guide uses a 2x selection rule [23]. Whatever factor you use, two facts from the sources bound the arithmetic: ratings do not add linearly across anchors [3], and the drywall itself is often the weak link, with a 1/8 in toggle falling from 31 lb in 1/2 in board to 27 lb in 3/8 in [21].

Choosing by load, quickly

• Up to about 20 lb, picture frames and smoke detectors: ribbed plastic expansion anchor, 3/16 or 1/4 in hole by gauge [8][19].
• 20 to 50 lb, towel bars and curtain rods: self-drilling anchor or molly bolt; the molly is the pick when the fixture will come on and off, since its sleeve stays threaded [8][25].
• 50 to 100 lb, shelves and heavy mirrors: wing toggle by bolt size, or a strap toggle if you want the bolt removable without losing the anchor [8][7].
• Above 100 lb, TV mounts and cabinets between studs: strap toggle at 238 to 275 lb ultimate, installed to one quarter of that as working load [4][8]. ITW and Albany County both still say the stud is the right answer when the load allows it [3][8].

Quick answers

• What size drill bit for a #8 plastic anchor? 1/4 in, per TrueTips and DGFloors; the SOS Metal line straddles #8 between its 3/16 and 1/4 ranges, so verify against the shank [15][16].
• What size hole for a 1/4 toggle bolt? 5/8 in for a spring wing (Albany County, Eugene Fastener); TOGGLER claims 3/4 in; a 1/4-20 SnapToggle needs only 1/2 in [6][8].
• What size bit for a molly bolt? 5/16 in for 1/8 in, 3/8 in for 3/16 in, 1/2 in for 1/4 in, matching the sleeve outside diameter [9][11].
• Do self-drilling anchors need a pilot hole? No. The E-Z Ancor line drills its own hole in 3/8, 1/2, and 5/8 in gypsum board [1][3]. In hard plaster a 1/8 in starter hole helps [15].
• Why is the toggle hole so much bigger than the bolt? The folded wings are 2 to 3x the bolt diameter and have to pass through; the bolt threads into the wing nut, not the wall [6][8].
• Can I redrill an oversize anchor hole bigger and use a larger anchor? For plastic and mollies, a too-loose hole is why anchors spin; move over or step up to a toggle in the same hole, since a toggle's hole is oversized by design [15][16].

Related guides

Also on this site: the concrete anchor drill bit chart owns the masonry side of the split (wedge, sleeve, Tapcon), the pilot hole chart sizes the wood-side hole when this anchor's screw also passes through framing, drywall screw sizes covers the screws that hold the board itself to studs, self tapping vs self drilling screws explains the sheet-metal screw threads these anchors accept, how to remove a broken drill bit covers the wall-side extraction when a bit snaps mid-hole, and drill bits by material picks the bit itself. When the plug's packaging is gone and the bit has to be matched by measuring, how to measure a drill bit size covers the caliper and gauge methods. For the plaster and tile surfaces these anchors sometimes go into, see drilling into tile.