Common fireplace insert dimensions generally range between 20 to 23 inches tall and 24 to 34 inches wide. Common depths of fireplace inserts range between 15 and 20 inches.
According to The Chimney Sweep, the Super from Pacific Energy, a plate steel model, measures 21 inches tall, 24 inches wide and 18 inches deep. From Hearthstone, the cast iron Morgan model measures 23 inches tall, 26 inches wide and 15 inches deep. The Neo 2.5 plate steel model from Pacific Energy measures 22 inches tall, 34 inches wide and 20 inches deep, while the cast iron Clydesdale from Hearthstone measures 23 inches tall, 33 inches wide and 15 inches deep.