Norwood Scale: The 7 Stages of Male Hair Loss Explained

The Norwood scale (also called the Hamilton-Norwood scale) grades male pattern hair loss from stage 1, little or no hair loss, to stage 7, where only a horseshoe-shaped band of hair is left on the sides and back (ISHRS). Dr. O'Tar Norwood published it in 1975 after studying 1,000 men, and it is still the most widely used system worldwide (Gupta and Mysore, 2016). Your stage helps describe your hair loss, but it does not by itself tell you how many grafts you need or whether you are a good candidate for surgery.

The 7 Norwood stages

The descriptions below follow Norwood's definitions as summarized in a 2016 review in the Journal of Cutaneous and Aesthetic Surgery (Gupta and Mysore) and the Cleveland Clinic.

The "A" variants

Norwood also described a less common type A pattern. Here the hairline moves straight back from front to rear without leaving an island of hair at the front, and a separate bald spot does not form at the crown. The remaining hair on the sides tends to be wider and sit higher on the head. There are four A types: 2A, 3A, 4A and 5A, depending on how far back the hairline has moved. Hair loss beyond 5A looks the same as stage 6 or 7 (Gupta and Mysore, 2016).

How common is each stage?

Male pattern hair loss is very common. MedlinePlus, from the National Library of Medicine, says it affects an estimated 50 million men in the U.S., and that more than half of men over 50 have some hair loss (MedlinePlus). The ISHRS says it can affect up to 50% of men by age 50 and up to 80% by age 80.

Norwood's 1975 paper reported how often each stage appeared at different ages, in 1,000 white men (Southern Medical Journal, 1975). We could not open the full tables, so we don't quote numbers by stage. That study is also old and included only white men. The Cleveland Clinic notes that pattern hair loss is less common in men of Chinese or Japanese descent and differs by ancestry (Cleveland Clinic).

How reliable is the Norwood scale?

Not as reliable as many people assume. In a Korean study, 40 doctors (dermatologists, dermatology residents and general doctors) graded the same 100 sets of photos with two systems. The Norwood-Hamilton scale had the lowest match rate between graders, and a newer system called BASP (basic and specific) did better (Journal of Dermatology, 2013). The 2016 review also says the Norwood scale leaves out some patterns and "is not very helpful in determining the surgical method" (Gupta and Mysore).

In practice, this means two clinics may give you different stages from the same photos. A stage 3 from one clinic and a stage 4 from another is not unusual, and it is not proof that one of them is wrong. Photos taken in different light or with wet hair can also make hair loss look different.

Women's hair loss uses different scales, such as the Ludwig scale, because the pattern is usually diffuse thinning on top rather than a receding hairline (Gupta and Mysore). See our guide to hair transplants for women.

What your stage means for a hair transplant

A transplant moves hair from the back and sides of the head, which resist balding, into the thinning areas. That donor area is limited, and the ISHRS warns that, as men age, the bald area keeps growing while the donor supply shrinks: "The goal is to never run out of donor hair" (ISHRS). That is why stage matters, but only together with other facts.

Early stages (1 to 3)

Hair loss at these stages may still be getting worse, and the future pattern is hard to predict. The ISHRS says surgeons do not typically recommend transplants for anyone younger than 20. It suggests trying finasteride and minoxidil first and checking again after 12 months (ISHRS). Its description of the ideal FUE candidate is someone whose hair loss has been stabilized with medicine, who is "preferably older," and who has enough donor hair for the transplant plus reserves for the future (ISHRS). Our guide to finasteride and hair transplants covers the medicine side.

Middle stages (3 vertex to 5)

This is where many men first look into surgery. The main questions are how much donor hair you have, whether your hair loss is still moving, and what you want to cover first. The ISHRS young-patient page says that when surgery is done on young patients, it should not be in the crown (ISHRS).

Advanced stages (6 and 7)

The bald area is large, and the donor area is often thinner. A transplant may still help, but full, thick coverage of the whole top may not be possible. Ask the surgeon to show you, on your own scalp, which areas they plan to cover and how much donor hair they will leave for later.

Graft numbers by stage

You will see charts online that give a graft count for each Norwood stage. We did not find one from the ISHRS or a peer-reviewed source that we could check, and the Norwood scale was not designed to measure area. Graft needs depend on the size of the bald area, your donor density, hair thickness and the density you want. Our guide to how many grafts you need explains how surgeons estimate it.

If you are getting quotes from clinics abroad

Clinics in Turkey and elsewhere often grade your stage and estimate grafts from a few phone photos. Treat that as a first guess, not a plan. Ask:

• Which Norwood stage they gave you, and whether a doctor or a salesperson made that call.
• How they measured your donor area, and how many grafts they think it can safely supply over your lifetime.
• Which areas this session will cover, and what happens if your hair loss keeps progressing.
• Whether a licensed doctor, not a technician, will do the key parts of the surgery. The ISHRS warns about unlicensed technicians doing graft harvesting (ISHRS).

Our checklist of questions to ask a hair transplant clinic goes further, and our guide to hair transplants in Turkey covers the trip itself.