Assessment tool
Hair loss scale
The Norwood scale stages male-pattern hair loss and the Ludwig scale stages female-pattern thinning. Pick the description that matches to see your stage.
Which scale fits you?
The Norwood scale describes male-pattern loss at the temples and crown. The Ludwig scale describes diffuse thinning across the top of the scalp.
About the Norwood and Ludwig scales
The Norwood scale is the standard reference for male-pattern hair loss. It runs through seven stages, from a full hairline to a horseshoe band of hair at the sides and back, tracking recession at the temples and thinning at the crown. The Ludwig scale is the standard for female-pattern hair loss. It uses three stages and describes diffuse thinning across the top of the scalp, with the frontal hairline usually preserved.
The male-pattern scale began with James Hamilton in the 1950s and was revised by O'Tar Norwood in 1975, which is why it is sometimes called the Norwood-Hamilton scale. Erich Ludwig published the female-pattern scale in 1977. Both remain the common language clinicians and researchers use to describe the pattern and extent of loss.
Staging helps a clinician describe where you are, set realistic expectations for treatment and track change over time. It is a visual estimate, not a diagnosis. A clinician confirms the pattern and rules out other causes of shedding, such as thyroid disease, iron deficiency or telogen effluvium, before recommending treatment.
Common questions
What is Norwood Stage 3?
Stage III is deep recession at both temples, sometimes with early thinning at the crown. It is usually considered the first stage of cosmetically noticeable balding and is a common point at which people start treatment. The recession forms the classic M, U or V shape at the hairline.
What is the difference between the Norwood and Ludwig scales?
The Norwood scale stages male-pattern hair loss, which recedes at the temples and thins at the crown, across seven stages. The Ludwig scale stages female-pattern hair loss, which thins diffusely across the top of the scalp while the frontal hairline stays intact, across three stages.
What stage of hair loss should I start treatment?
Evidence consistently favors starting earlier, while more hair is present to keep. Finasteride and minoxidil are most studied from around Norwood Stage II to III and Ludwig Stage I onward. A clinician decides based on your pattern, how fast it is progressing and your goals.
What is Ludwig Stage 2?
Ludwig Stage II is a clearly widened part with visible thinning across the top of the scalp, more pronounced than the subtle volume loss of Stage I. The frontal hairline remains intact, which is the hallmark that separates female-pattern thinning from male-pattern recession.
Can hair grow back at Norwood Stage 5 or 6?
At advanced stages, treatment can slow further loss but significant regrowth is less likely, because follicles that have fully miniaturized do not usually recover. The evidence for regrowth is strongest at earlier stages, which is why earlier treatment tends to give better results.