Hair transplantation is an advanced procedure that requires precision at every stage. One of the key elements for success is the proper distance between the follicular units (dwelling units) in hair transplantation. How do you calculate this distance and why does it matter for a natural look? In this article, we’ll explain what determining the spacing is, what the best benchmarks are and how it affects the results. How many grafts per cm2 can be implanted and how are they best spaced? If you are planning a procedure, keep reading!

Read also: Can too many grafts be implanted per cm2?

how many hairs per cm2
Paper published in Hair Transplant Forum International – How many grafts per cm2?

What are housing units and why does distance matter?

Residential units (grafts, follicles) are natural groups of hair (1-4 hairs) that are taken and transplanted during the procedure. The distance between the housing units in hair transplantation determines the density and aesthetics of the end result. Too little distance can lead to an overloaded area, while too much distance can lead to sparse hair growth. Finding the balance is key, which requires the surgeon’s experience.

How to calculate the distance between housing units?

An article from Hair Transplant Forum International (September/October 2001) by Francisco Jimenez and Jose M. Rufernandez presents the formula:
L= k/√n, where:

  • L – distance between elements (in millimeters),
  • k – a constant that depends on the implantation pattern,
  • n – the number of elements per unit area (e.g., per square centimeter).

The distance between housing units in hair transplantation depends on the pattern of hair implantation, i.e. square or triangular. Triangular is considered more effective, giving a denser distribution (up to 15% more units per unit area).

Implantation patterns – square or triangular?

The distance between housing units in hair transplants can be determined in two ways:

  • Square pattern: simpler to calculate, with even distribution
  • Triangular pattern: optimal for density, increases number of units
how many grafts per cm2 of hair kierach warsaw transplantation
How many grafts per cm2?

The authors suggest that the triangular pattern is more efficient, resulting in a more natural hair transplantation effect.

How does distance affect transplant outcomes?

The distance between housing units in hair transplants has a key impact on the outcome:

  • Density: A smaller distance (e.g. 1-2 mm) gives a denser hairstyle, but requires more grafts.
  • Naturalness: too tight a spacing can look unnatural, and too large a spacing – rarely growing hair.
  • Healing: Adequate distance minimizes the risk of damaging existing hair follicles.

The hair transplant doctor must adjust the spacing according to the condition of the skin and the number of grafts available in order to plan the procedure wisely and give the patient a satisfactory result.

How do I prepare for the procedure considering the distance?

To ensure optimal distance between housing units in hair transplantation:

  • Consultation: discuss the expected density with your doctor.
  • Skin analysis: Assessment of skin quality and donor hair density.
  • Planning: the surgeon plans the density of hair implantation based on the available number of grafts and the area to be restored.

After treatment, avoid stretching the skin for 2-3 weeks.

Advantages and limitations

Advantages

  • Precise distance planning ensures a natural effect.
  • The triangular pattern increases efficiency.
  • Minimal impact on existing hair.

Restrictions

  • It requires the experience of a surgeon.
  • Limitations on the number of grafts can affect density.
  • It has less significance in very advanced baldness.

Distance between housing units – Myths and facts

  • Myth: “The smaller the distance, the better the results.”
  • Fact: Too little distance can harm bellows.
  • Myth: “Patterns are irrelevant.”
  • Fact: The triangular pattern gives better results.

Where to perform the procedure?

The distance between housing units in hair transplantation is best planned by clinics that specialize in FUE or FUT procedures. The cost depends on the number of grafts to be taken and the patient’s expectations for density. Choose a facility with modern equipment and an experienced team.

natural fue hairline
How many grafts per cm2? Best to mimic the patient’s natural density.

Is it possible to implant hair too densely?

Transplanting hair too densely can have serious consequences, affecting both aesthetics and the patient’s health. Hair transplantation, especially Follicular Unit Extraction (FUE) or Follicular Unit Transplantation (FUT), requires precise planning to ensure a natural look and lasting results. However, if follicular units (FUs) are planted too close together, a number of problems can occur. In this article, we will discuss why the distance between FUs is crucial and what the consequences of too dense implantation can be.

Consequences of too dense implantation

Studies indicate that implanting grafts too densely can lead to several negative effects:

  • Poor hair growth: When FUs (follicular units, grafts) are too close, they compete for resources such as blood and nutrients, which can result in poor growth or even death of some grafts.
  • Unnatural Appearance: Implantation that is too dense can create a “pluggy” effect, or unnatural-looking clusters of hair, which spoils the aesthetics.
  • Health complications: Too dense implantation increases the risk of infection, skin necrosis (especially in smokers) and healing problems, as the skin may not be able to keep up with regeneration.
  • Limitations of the intake area: overuse of FU from the donor area can lead to thinning, which negatively affects future treatments.

Summary – How many grafts per cm2?

The distance between dwelling units in hair transplantation is the key to a natural and dense result. The formula L = k/√n allows you to calculate the spacing accurately, and the triangular pattern proves to be the most effective. However, this is theory, and in practice it is best to mimic nature and try to implant hair with a density similar to the patient’s natural density. In an ideal world, when the limit on follicle harvesting does not exist, one could plan for extremely dense hair implantation, but usually we are limited.

However, this does not mean that a natural hairline or very good density cannot be achieved. It all depends on the experience of the doctor performing the procedure. If you’re planning a transplant, consult with your doctor to customize a plan to suit your needs. Don’t wait – make an appointment and start your road to regaining a full head of hair today! How many grafts per cm2 will be appropriate is based on the number of follicles taken and the size of the area to be restored.

We also recommend the article: How much hair can be harvested in one transplant?

You can read more about hair transplantation HERE. If the problem concerns you, we invite you to CONTACT us. You can also schedule a visit ON-LINE. Visit us on Instagram and TikTok.

artur kierach hair transplantation
Artur Kierach hair transplantation. How many grafts per cm2?

How many grafts per cm2? How many grafts per cm2? How many grafts per cm2?