Hair Donor Index

Hair transplant results are only as good as the quality of the donor area. At DK Klinik, we put forward developed the Hair Donor Index — a scientifically grounded, easy-to-understand scoring system designed to assess a patient's donor area potential and predict the likely success of a hair transplant.

Understanding the Hair Donor Index

The Hair Donor Index is a standardized evaluation method that assigns a score from 0 to 100 based on the structural quality of a patient's donor area.

It helps both doctors and patients understand whether a person is a suitable candidate for hair transplant surgery, how extensive the procedure can be, and what kind of results they can realistically expect.

This system is based on four core scientific parameters:

1. Follicular Density

2. Donor Area Size

3. Follicular Unit Distribution

4. Hair Thickness

Each of these parameters is scored in tiers (Low, Medium, High) and then multiplied by a weighted coefficient based on its clinical significance.

Why We Created the Hair Donor Index

Most clinics rely solely on visual inspection and subjective judgment when evaluating donor areas. While expert eyes are important, they can be inconsistent or hard to communicate with patients. We wanted to create a quantitative, objective, and repeatable method that:

• Enables better surgical planning

• Standardizes case comparisons

• Provides patients with transparent, measurable insight

Moreover, in daily clinical practice, we often see how traditional classification systems like the Norwood-Hamilton scale fall short.

While the Norwood scale is useful for describing the pattern and severity of male pattern baldness, it doesn't offer insight into the feasibility of restoring that hair.

In many consultations, patients are told they are "Norwood 4" or "Norwood 5," and clinics attempt to estimate how many grafts would be required to cover the balding areas.

However, what truly matters is whether the donor area can support such an extraction without being overharvested. Norwood classifications can describe the demand, but they say nothing about the supply.

That’s where the Hair Donor Index comes in. It evaluates the availability side of the equation. This allows clinics to provide realistic planning that aligns both with the patient’s goals and their actual donor capacity.

The Four Key Parameters

1. Donor Area Size (Weight: ×7)

Method of Measurement: Manual measurement using a ruler

Measured from ear to ear and vertically across the nape, the size of the safe donor area determines how many grafts can be harvested without visible thinning.

1 Point (Low): Less than 5 cm
3 Points (Medium): Between 5 and 8 cm
5 Points (High): Greater than 8 cm

2. Follicular Density (Weight: ×6)

Method of Measurement: Densitometry

The occipital region was averaged by counting follicular units from various standard regions.

1 Point (Low): Below 50 FU/cm²
3 Points (Medium): Between 60 and 65 FU/cm²
5 Points (High): Above 65 FU/cm²

3. Follicular Unit Distribution (Weight: ×5)

This looks at whether most follicular units are single-hair grafts or multi-hair grafts. Multi-hair units provide more volume and better coverage.

1 Point (Low): 40% or more single-hair follicular units
3 Points (Medium): Balanced distribution of single- and multiple-hair follicular units
5 Points (High): More than 40% triple-hair or larger follicular units

4. Hair Thickness (Weight: ×2)

Thicker hair offers better coverage and visual density, although it's the least influential parameter.

Measurement method: Digital micrometer

1 Point (low) under 65 μm
3 Points (medium) 65-80 μm
5 Points (high) above 80 μm

Additional Influential but Non-Core Factors

🔹 Age and Donor Area Stability:

Donor area characteristics are not static throughout life. As patients age, even genetically stable zones may experience miniaturization or reduced density due to age-related hormonal changes or the progression of androgenetic alopecia. This means that the Hair Donor Index reflects a snapshot in time and should be periodically re-evaluated—especially in younger patients who are still undergoing changes in hair pattern and density.

While the Hair Donor Index focuses on the four parameters above for scoring, there are additional biological and cosmetic variables that can influence hair transplant outcomes. These factors are not currently scored in the index, as they are either less objective, highly variable, or manageable with surgical techniques.

🔹 Skin Elasticity (Scalp Laxity):

Scalp flexibility can affect how easily grafts can be harvested and how well the area heals. However, modern surgical techniques and instrumentation often minimize the impact of lower laxity.

🔹 Curliness or Hair Texture:

Curly or wavy hair provides greater visual density per graft, but scoring this is challenging due to ethnic and individual variations.

🔹 Hair-to-Skin Color Contrast:

Lower contrast between hair and scalp color results in more natural-looking density. This is a cosmetic factor that improves perceived coverage but does not alter graft quantity.

These variables are considered during physician evaluation, but not included in the score to maintain standardization and repeatability. They may be noted in consultation reports or affect planning decisions.

How the Score Is Calculated

Each parameter is assigned a score (1, 3, or 5) and then multiplied by its respective weight. The sum of all four weighted scores yields the Hair Donor Index, a final score between 20 and 100.

Hair Donor Index Score Classification

To help patients understand their scores better, we divided the results into four categories, based on the actual scoring range (minimum score being 20)

A Tool Against Subjectivity in Global Hair Transplantation

The donor area is evaluated differently by different doctors, and comments on whether the donor area is limited or not are often subjective. Meanwhile, hair transplantation has increasingly become a procedure performed abroad—thanks to its affordability and the growing number of specialized clinics.

This increase in clinic numbers has allowed patients to easily receive multiple opinions and offers, making comparisons between clinics more accessible.

However, it also opens the door for some providers to act with purely commercial motives, offering misleading or overly optimistic evaluations of a patient's donor area or graft potential.

In this context, the Hair Donor Index can serve as a reliable reference point for patients.

Even before committing to surgery, individuals can use this system to understand whether their donor area is truly suitable, helping to avoid exaggerated promises and unrealistic expectations.

Scientific Integrity & Transparency

While traditional donor evaluations are often subjective, the Hair Donor Index introduces a semi-standardized, data-supported methodology into hair transplantation. It is based on clinical experience, thousands of patient cases, and carefully structured measurement criteria.

Although it is not yet a universally validated scientific scale, it aligns with the quality principles of leading transplant associations and provides a structured framework for retrospective studies, case evaluations, and clinic benchmarking.

At DK Klinik, our doctors use this index to:

• Create realistic patient expectations based on measurable parameters

• Optimize surgical design (DHI or FUE)

• Track improvements or degradation in donor area quality over time

FAQs About the Hair Donor Index

Q: Can I improve my Donor Index score over time?

A: No. The Donor Index evaluates anatomical features like hair density and scalp size. These are largely genetic and do not change significantly.

Q: Is this score permanent?

A: Not exactly. The Hair Donor Index reflects the current state of your donor area and is subject to change over time. Factors like aging, progression of androgenetic alopecia, or scarring can affect hair density and distribution, potentially lowering your score in future evaluations.

Q: Does a lower score mean I can't get a hair transplant?

A: Not necessarily. Even patients with "Fair" scores may benefit from targeted procedures or alternative treatments.

Ready to Discover Your Hair Donor Index?

Book your consultation with DK Klinik and receive your personalized Hair Donor Index report. Our team will analyze your donor area using our proprietary system and help you make the most informed decision for your hair restoration journey.

Hair Donor Index — A smarter, scientific way to plan your hair transplant.