Which characters are in which weight groups?

According to chat:

Characters are divided into weight groups. Each character in a weight group has identical stats.

What are the different weight groups, and which characters are in each?

There are 30 playable characters in Mario Kart 8, consisting of 16 default characters and 14 unlockable characters. ...There are 3 weight classes dependent on the size of the kart the characters ride on (with the exception of Metal Mario and Pink Gold Peach): light, medium, and heavy.

Source: Mario Kart 8 - Mario Wiki

Light

Speed 2.25 Acceleration 3.25 Weight 2.25 Handling 4.75 Traction 4.5

• Baby Mario
• Baby Luigi
• Baby Peach
• Baby Daisy
• Baby Rosalina
• Lemmy

Speed 2.75 Acceleration 3 Weight 2.75 Handling 4.25 Traction 4.25

• Toad
• Koopa Troopa
• Shy Guy
• Larry
• Wendy
• Lakitu
• Toadette

Medium

Speed 3.25 Acceleration 2.75 Weight 3.25 Handling 3.75 Traction 4

• Peach
• Daisy
• Yoshi

Speed 3.75 Acceleration 2.5 Weight 3.75 Handling 3.25 Traction 3.75

• Iggy
• Ludwig
• Mario
• Luigi

Heavy

Speed 4.25 Acceleration 2.25 Weight 4.25 Handling 2.75 Traction 3.5

• Donkey Kong
• Waluigi
• Rosalina
• Roy

Speed 4.25 Acceleration 2 Weight 4.75 Handling 2.75 Traction 3.25

• Metal Mario
• Pink Gold Peach

Speed 4.75 Acceleration 2 Weight 4.75 Handling 2.25 Traction 3.25

• Morton
• Bowser
• Wario

A complete list of weight classes, differences within the weight classes, karts and items can be found on the Mario Wiki.