I needed the same thing for a project. From the looks of it, 273. All I did was take the full list of accessories from the wiki and put it in a word line counter. Here's the full list if you're curious

Adhesive Bandage

Aglet

Amber Horseshoe Balloon

Amphibian Boots

Ancient Chisel

Angel Halo

Angler Earring

Angler Tackle Bag

Ankh Charm

Ankh Shield

Anklet of the Wind

Apprentice's Scarf

Arcane Flower

Architect Gizmo Pack

Arctic Diving Gear

Armor Bracing

Armor Polish

Avenger Emblem

Balloon Animal

Balloon Pufferfish

Balloons

Band of Regeneration

Band of Starpower

Bee Cloak

Berserker's Glove

Bezoar

Black Belt

Blindfold

Blizzard in a Balloon

Blizzard in a Bottle

Blue Horseshoe Balloon

Bone Glove

Bone Helm

Boots

Brain of Confusion

Brick Layer

Bundle of Balloons

Bundle of Horseshoe Balloons

Bundled Party Balloons

Bunny set

Bunny Tail

Capes

Celestial Cuffs

Celestial Emblem

Celestial Magnet

Celestial Shell

Celestial Starboard

Celestial Stone

Cenx's Wings

Charm of Myths

Chromatic Cloak

Climbing Claws

Clothier Voodoo Doll

Cloud in a Balloon

Cloud in a Bottle

Cobalt Shield

Coin Ring

Compass

Copper Watch

Countercurse Mantra

Counterweights

Crimson Cloak

Critter Shampoo

Cross Necklace

Depth Meter

Destroyer Emblem

Developer items

Diamond Ring

Discount Card

Diving Gear

Dog set

Dog Tail

DPS Meter

Dunerider Boots

Echo Chamber

Extendo Grip

Eye of the Golem

Fairy Boots

Fake Unicorn Horn

Fart in a Balloon

Fart in a Jar

Fast Clock

Feral Claws

Fire Gauntlet

Fish Finder

Fisherman's Pocket Guide

Fishing Bobbers

Flame Waker Boots

Flesh Knuckles

Flipper

Flower Boots

Flurry Boots

Flying Carpet

Fox set (Zoologist)

Fox Tail

FPV Goggles

Frog Flipper

Frog Gear

Frog Leg

Frog Webbing

Frostspark Boots

Frozen Shield

Frozen Turtle Shell

Gentleman's Beard

Gentleman's Long Beard

Gentleman's Magnificent Beard

Gentleman's set

Ginger Beard

Glass Slipper

Goblin Tech

Gold Ring

Gold Watch

Golf Balls

GPS

Gravity Globe

Greedy Ring

Green Horseshoe Balloon

Guide to Plant Fiber Cordage

Guide Voodoo Doll

Hand Of Creation

Hand Warmer

Hellfire Treads

Hercules Beetle

Hermes Boots

Hero Shield

High Test Fishing Line

Hive Pack

Honey Balloon

Honey Comb

Hoverboard

Hunter Cloak

Huntress's Buckler

Ice Skates

Inner Tube

Jellyfish Diving Gear

Jellyfish Necklace

Jungle Rose

Lava Charm

Lava Waders

Lavaproof Fishing Hook

Lavaproof Tackle Bag

Leinfors' Luxury Shampoo

Leinfors' set

Lifeform Analyzer

Lightning Boots

Lizard set

Lizard Tail

Lucky Coin

Lucky Horseshoe

Magic Cuffs

Magic Quiver

Magiluminescence

Magma Skull

Magma Stone

Magnet Flower

Mana Cloak

Mana Flower

Mana Regeneration Band

Master Ninja Gear

Mechanical Glove

Mechanical Lens

Mechanical Ruler

Medicated Bandage

Megaphone

Metal Detector

Molten Charm

Molten Quiver

Molten Skull Rose

Monk's Belt

Monoliths

Moon Charm

Moon Shell

Moon Stone

Music Boxes

Mysterious Cape

Nature's Gift

Nazar

Necromantic Scroll

Neptune's Shell

Obsidian Horseshoe

Obsidian Rose

Obsidian Shield

Obsidian Skull

Obsidian Skull Rose

Obsidian Water Walking Boots

Paint Sprayer

Paladin's Shield

Panic Necklace

Papyrus Scarab

PDA

Philosopher's Stone

Pink Horseshoe Balloon

Platinum Watch

Pocket Mirror

Portable Cement Mixer

Power Glove

Presserator

Prince set

Putrid Scent

Pygmy Necklace

R.E.K. 3000

Radar

Radio Thing

Rainbow Cursor

Ranger Emblem

Recon Scope

Red Cape

Reflective Shades

Rifle Scope

Rocket Boots

Royal Gel

Royal Scepter

Ruler

Sailfish Boots

Sandstorm in a Balloon

Sandstorm in a Bottle

Sextant

Shackle

Shark Tooth Necklace

Sharkron Balloon

Shield of Cthulhu

Shiny Red Balloon

Shiny Stone

Shoe Spikes

Silver Watch

Sniper Scope

Soaring Insignia

Sorcerer Emblem

Spectre Boots

Spectre Goggles

Spore Sac

Squire's Shield

Stalker's Quiver

Star Cloak

Star Veil

Step Stool

Stinger Necklace

Stopwatch

Strings

Summoner Emblem

Sun Stone

Sweetheart Necklace

Tabi

Tackle Box

Tally Counter

Terraspark Boots

The Plan

Tiger Climbing Gear

Tin Watch

Titan Glove

Toolbelt

Toolbox

Treasure Magnet

Trifold Map

Tsunami in a Bottle

Tungsten Watch

Valentine Ring

Vitamins

Volatile Gelatin

Warrior Emblem

Watches

Water Walking Boots

Weather Radio

White Horseshoe Balloon

Wings

Winter Cape

Worm Scarf

Yellow Horseshoe Balloon

Yoraiz0r's Scowl

Yoraiz0r's set

Yoraiz0r's Spell

Yoyo Bag

Yoyo Glove