Norwood Scale: Causes, Stages & Treatments (2024)

Male pattern hair loss is an extremely common condition. It affects half of all men by the time they’re 50 — with some people beginning tolose hair as early as their late teens or early 20s[1] [2].

While pattern baldness (also known asandrogenetic alopecia) affects most men at some point in their life, the degree of hair loss — and the impact on your life — varies enormously. As a result, many researchers have proposed ways to classify and measuremale pattern baldness. The best-known classification is called the Norwood scale.

Find out how the Norwood scale describes each stage of male pattern baldness, and how it’s used to measure hair loss and propose potential hair restoration treatments.

Table of Contents

What is the Norwood scale?

Although the Norwood scale has been around for some time — it was first proposed in 1975 — it’s still the most popular scale for diagnosing male pattern hair loss worldwide [3]. This is because it’s easy to understand and has a high level of detail.

The Norwood scale (also sometimes known as the Hamilton-Norwood scale, as it builds on the 1951 Hamilton classification chart) was devised following the study of hair loss in 1,000 male patients. It’s now used to define, diagnose, and predict hair loss patterns in men experiencing androgenetic alopecia.

Many hair restoration clinics also use this scale to determine the number of hair grafts required forhair transplant surgeryand in turn, provide price quotations for hair transplantation. We recommend reading our UK analysis if you are interested in understandinghair transplants costsin the UK. You can also find out more about thecost of a crown hair transplant.

The Norwood scale splits male pattern hair loss into 7 distinct stages of hair loss, which focus mainly on typicalhair loss around the templesand crown.

The 7 stages of male pattern hair loss

Each stage of male pattern baldness is characterised by a specific amount of hair loss in a given area. Here’s how the scale defines each stage of hair loss.

Stage 1

The first stage refers to a standard adult hairline with little or no hair loss or balding. There’s also no hair loss around the crown. You may notice a little shedding around the temples, but this doesn’t manifest in visible hair loss at this stage.

Average grafts required to restore hair: 0

The hairline starts to recede slightly at the temples atNorwood 2, though there’s still no visible thinning around the crown. This is sometimes considered a mature hairline. You may also see slightly morehair thinning on one side of the headthan on the other. While you may be concerned about this recession, the Norwood scale considers this hairline to be unaffected by patterned hair loss.

Average grafts required to restore hair: 500-1,000

Stage 3/stage 3 vertex

This is the earliest stage that the Norwood scale considers balding. The hairline recedes more dramatically, with a typical M-shaped hairline pattern starting to form at the temples. Alternatively or in addition, you might start to see thinning around your crown (this is known as stage 3 vertex).

See moreNorwood 3 stages of hair lossand results from hair restoration surgery.

Average grafts required (temple): 1,000-1,500
Average grafts required (crown): 500-1,000

Stage 4

Norwood stage 4 hair loss consists of more extensive hair loss in the same areas as stage 2 and 3: namely, the temples and the crown. However, there’s still a substantial amount of hair separating the crown from the hairline. If no hair is lost from the crown, then the hairline recession will be much greater than in stage 3.

Average grafts required (temple): 1,200-2,500
Average grafts required (crown): 800-1,100

Stage 5

In this stage, hair loss on the crown and temples increases. The hair separating the 2 areas is still there but becomes thinner as more hair is lost. If no hair is lost from the crown, the hairline recession is much greater than atNorwood stage 5than during stage 4.

Average grafts required (temple): 1,800-2,500
Average grafts required (crown): 1,000-1,500

Stage 6

AtNorwood stage 6, the band of hair separating the crown from the receding hairline starts to disappear. There is significant hair loss around the front and top of the head. If there has been no balding at the crown, the hairline now recedes almost to the back of the head.

Average grafts required (temple): 1,800-2,500
Average grafts required (crown): 1,500-1,700

Stage 7

This is the most advanced stage of hair loss according to the Norwood scale. There is typically just a band of hair remaining around the sides and back of the head. The top of the head is almost completely bald if not covered by sparse hair. By this point, it may be too late for a hair transplantation procedure, though there have been some successful examples of completely bald hair transplants.

Average grafts required (temple): 2,500+
Average grafts required (crown): 1,700+

How do trichologists use the Norwood scale?

When you have a hair loss consultation, a trichologist willexamine your hair and scalpto determine the cause and extent of your hair loss. The Norwood scale is a vital tool for diagnosing the level your hair loss.

At a basic level, a trichologist can use the Norwood scale to determine the current stage of your hair loss. This enables them to recommend hair loss treatments for your existing hair loss. If you’re diagnosed with hair loss in the early stages (usually 2 or 3) your trichologist may recommend or topical solutions like Minoxidilto retain the remaining hair and promote healthy hair growth.

The Norwood scale can also be used to predict how your hair loss will progress through each scalp zone:

Male pattern baldness is largely hereditary, so in conjunction with knowledge of your family history, a trichologist can use the Norwood scale to suggest where your hair loss will stop [4]. This enables you to plan for your potential future hair loss. You can reduce current shedding, stimulate hair growth, and prepare for a future hair transplant if necessary.

Trichologists can only use the Norwood scale to make diagnoses and predictions based on male pattern baldness. It can’t be used forfemale pattern baldness(theLudwig scaleis often used for this) or temporary hair loss liketelogen effluvium[3].

At which Norwood stage should you seek hair loss treatment?

No matter which Norwood stage you’re at, if you’re worried about your hair loss, you should seek help from a professional trichologist. In many cases, the earlier your hair loss is addressed, the better — tackling the problem early can minimise or even prevent the need for hair transplants.

If your hair loss is advanced, you may still be eligible for a hair transplant.Get a free hair loss examinationat the Wimpole Clinic to find out if a hair transplant is right for you.

1. Male pattern baldness: classification and incidence
2. An Overview of Alopecias
3. Classifications of Patterned Hair Loss: A Review
4. Understanding Pattern Hair Loss-Hair Biology Impacted by Genes, Androgens, Prostaglandins and Epigenetic Factors
5. Finasteride: a review of its use in male pattern hair loss
6. Effectiveness Of 5% Minoxidil In Treating Male-Pattern Hair Loss
7. Reliability of Hamilton-Norwood Classification