Refers to a person's height or stature, often with a nuance of build or physical presence. The reading せいたけ is less common but acceptable.
He is tall in stature.
The child's height has increased.
My child's height shot up a lot over the past year.
Grass as tall as a person had grown in the garden.
I had the clothes tailored to fit my height.
背 is a broader, more casual word that can mean 'back' or 'height', whereas 背丈 specifically and unambiguously refers to a person's height.
背丈 specifically means a person's standing height, while 丈 is a broader, more literary term that can also describe garment length or feelings.
Standard kanji spelling. The reading せたけ is the most common.
Search-only form; not a standard spelling.
Rarely used kanji form; 背丈 is strongly preferred.
Compound of 背 (se, 'back; height') and 丈 (take, 'length; stature'). The reading せたけ is a regular compound reading; せいたけ preserves an older reading of 背.