The 9 Human Design Centers: Defined, Undefined and Open

A Human Design center is one of the nine shapes on your bodygraph, the body-shaped diagram that is your chart. Each center handles one kind of energy or awareness: thinking, speaking, identity, willpower, life force, instinct, emotion, pressure. On your chart, each one is either colored in (defined) or left white (undefined or open).

That difference decides your Type and your Authority, and shows where you run the same way every day and where you pick up the people around you. Below: all nine centers on one page, with their gates, the classic not-self question for each, and how often each one is defined in a simulation of 4,000 random birth moments run with the YourHumanDesign chart engine.

If you want the layout of the whole diagram first (the red and black columns, the lines between centers), start with the bodygraph guide and come back.

All nine centers at a glance

How to read the last column. These are simulated shares, not counts of real people. Method: 4,000 random birth moments drawn evenly from 1950 to 2009, each computed with the YourHumanDesign chart engine (the one behind our free calculator), seed 20260927, run in September 2026. With N = 4,000 a share near 50% is accurate to about ±1.6 points. Real populations are not spread evenly across the calendar, so treat these as a guide to how the chart's geometry behaves.

The not-self questions are the ones commonly taught in the Human Design system; the Jovian Archive page on the nine centers describes the same themes center by center. The 64 gates split 3, 6, 11, 8, 4, 9, 7, 7 and 9 across the nine centers, which is why the Throat, with 11 gates and the most channels, turns up defined so often.

Defined, undefined and completely open

There are three states, not two.

• Defined. The center is colored in because at least one full channel connects it to another center. The Jovian Archive dictionary puts it the same way: a defined center is always connected to another defined center by a channel. This part of you works the same way whoever you're with.
• Undefined. The center is white, but one or more of its gates are active (you'll see the gate numbers highlighted, with no full channel attached). You have some fixed themes here, but no steady energy of your own.
• Completely open. The center is white and none of its gates are active. There is no fixed theme here at all, only what comes in from outside.

Both white states take in energy from the people and places around you and turn it up. An undefined Solar Plexus in a tense room can feel the tension more strongly than the tense person does. That is not a flaw: over time, the white centers are where you learn the most about other people.

A defined center is not "better". It's steady, and steady cuts both ways: reliable, but not flexible. The practical skill is knowing which of your feelings and pushes come from a defined center (yours, every day) and which arrive through a white one (worth checking before you act on them).

Your own definition never changes: it is fixed by your birth moment. What changes is the company. Passing planets (transits) can complete a channel for a while and make a white center feel defined, and the people you spend time with can do the same while you are with them.

Four kinds of center, and why they decide your Type

The centers fall into groups, and the groups are what the chart uses to work out your Type.

• Motors (4): Heart (Ego), Sacral, Solar Plexus and Root. These produce energy.
• Awareness centers (3): Ajna, Spleen and Solar Plexus. These are the three ways of knowing: mental, instinctive and emotional. The Solar Plexus is in both groups.
• Pressure centers (2): Head (mental pressure) and Root (physical pressure).
• Throat and G: the Throat is the center of expression; the G, in the middle, holds identity, love and direction.

Two rules follow from this, and the simulation shows them cleanly.

The Sacral decides Generator or not. A defined Sacral makes you a Generator or Manifesting Generator. In the 4,000 simulated charts the Sacral was defined in 69.6%, and Generators (36.6%) plus Manifesting Generators (33.0%) add up to exactly the same 69.6%.

A motor connected to the Throat makes you a "manifesting" type. If a chain of defined channels links any motor to the Throat, energy can go straight into action. With a defined Sacral that gives a Manifesting Generator; without one, a Manifestor. With the Sacral open, no motor linked to the Throat and at least one center defined, you are a Projector; with no centers defined at all, a Reflector. The types guide walks through each one.

How many defined centers is normal?

Most charts sit in the middle. In the same simulation (N = 4,000, September 2026):

The average was 4.79 defined centers out of 9. About two in three charts (67.9%) had four, five or six.

Three rows need a word. Exactly one defined center can't happen, because a channel always joins two centers, so definition comes in pairs at the least. Zero defined centers is the Reflector: 1.0% of the simulation, a close match for the usual "about 1 in 100". If most of your chart is white, the Reflector guide is worth a read even if you aren't one, because it describes the fully open experience.

All nine defined is the rarest chart that can happen: 0.7% of the simulation, with another 2.9% at eight. Nothing on such a chart is left white, so almost everything runs the same way whoever the person is with.

The Solar Plexus, Spleen, Heart and Root in depth

These four get more room here, because the Head, Ajna, Throat, G and Sacral already have guides of their own. Three of the four can be your authority; the Root never is.

The Solar Plexus: the emotional wave

The Solar Plexus is a motor and an awareness center at once. It carries feelings, moods and desire, and it moves in a wave: up, down and around again over hours or days. In Human Design terms, there is no full clarity at any single point on that wave.

• Defined (52.7% simulated): you have your own emotional rhythm. A defined Solar Plexus always gives Emotional authority, whatever else is defined. That's why the simulated Emotional authority share is also 52.7%. It outranks the Sacral, the Spleen and everything else.
• Open or undefined (47.3%): you feel other people's emotions and amplify them. The not-self pattern is keeping the peace at any cost: avoiding the conversation, the "no", the hard truth.
• Gates: 36, 22, 37, 6, 49, 55, 30. It connects to the Throat (12-22, 35-36), the Heart (37-40), the Sacral (6-59) and the Root (19-49, 39-55, 30-41).

The practical rule for a defined Solar Plexus is time. Big decisions get slept on, sometimes more than once. The Emotional authority guide covers how that works day to day.

The Spleen: instinct in the moment

The Spleen is the oldest of the three awareness centers in Human Design teaching. It speaks quietly, once, in the moment, as a sense of "this is fine" or "not this". It doesn't repeat itself and it doesn't argue.

• Defined (58.6% simulated): you have a steady instinct you can learn to trust. If your Solar Plexus and Sacral are both open, the Spleen becomes your authority: Splenic authority, 7.9% of the simulation.
• Open or undefined (41.4%): you can be very sensitive to other people's sense of safety and unease. The not-self pattern is holding on to people, jobs or habits that stopped being good for you, because letting go feels less safe than staying.
• Gates: 48, 57, 44, 50, 32, 28, 18. In Human Design each Spleen gate carries its own fear: inadequacy (48), the future (57), the past (44), responsibility (50), failure (32), a life without purpose (28) and authority, or being challenged and judged (18). These are read as fears to notice, not signs that something is wrong with you.

More on how the Spleen decides, including for Projectors and Manifestors, in the Splenic authority guide.

The Heart (Ego): willpower and promises

The Heart, also called the Ego or Will center, is the smallest center on the chart and has only four gates: 21, 40, 26 and 51. It's a motor, and it runs on willpower, self-worth, promises and the material side of life: work, money, the deal between giving and getting.

• Defined (37.7% simulated): you have a reliable will. You can make a promise and have the drive to keep it, as long as you also rest. Ego authority is rare: in the simulation, 0.7% had Ego Manifested authority (Manifestors) and 0.5% Ego Projected (Projectors).
• Open or undefined (62.3%): this is the motor most often left white. The not-self question here is "Do I have something to prove?" The pattern is overpromising, underpricing yourself, or pushing to show you're worth something.
• Channels: to the Throat (21-45), the G (25-51), the Spleen (26-44) and the Solar Plexus (37-40).

If your Heart is open, a useful habit is to notice when you're about to commit to something mainly to prove a point, and pause there.

The Root: pressure to get moving

The Root sits at the bottom of the chart and is both a pressure center and a motor. It produces the push to start, to finish, to get things off the list. It has nine gates: 58, 38, 54, 53, 60, 52, 19, 39, 41.

• Defined (60.3% simulated): you have a steady relationship with pressure. It's there, it comes in pulses, and you tend to work with it rather than be run by it.
• Open or undefined (39.7%): you take in outside pressure and turn it up. The not-self pattern is rushing to clear the pressure so you can finally feel free, then finding more pressure waiting.
• Channels: the Root never connects straight to the Throat. It feeds three centers, with three channels each: the Spleen (18-58, 28-38, 32-54), the Sacral (3-60, 9-52, 42-53) and the Solar Plexus (19-49, 39-55, 30-41).

Nine of the 36 channels touch the Root. The channels guide has the full list of 36.

The other five, briefly

Short notes, with links to the full guides.

• Head (defined 26.6% simulated): the least often defined center. It produces questions and inspiration, not answers. Gates 64, 61, 63. See the Head and Ajna guide.
• Ajna (46.1%): the downward triangle under the Head. It turns questions into concepts and opinions. A defined Ajna processes information one fixed way; an open one can see many angles and may feel pressure to sound certain.
• Throat (68.9%): the most connected center, with 11 gates. A motor linked to the Throat is what makes a Manifestor or a Manifesting Generator. See the Throat and G center guide.
• G center (59.0%): the diamond in the middle, with eight gates. Identity, love and direction. An undefined G tends to find its direction through places and people, which is why "am I in the right place?" matters so much for it.
• Sacral (69.6%): the life-force motor, defined only in Generators and Manifesting Generators. It answers with a gut sound, not with reasons. See the Sacral center guide.

Worked example: one fictional chart, center by center

Here is a chart computed with our engine for a made-up birth moment: 30 May 1981, 07:55, Dublin. This person does not exist. The example is here to show how the centers combine.

Defined: Throat, Heart, Spleen, Solar Plexus, Root (five, about average).

Undefined, with active gates: Ajna (gate 11), G (gates 15 and 46), Sacral (gates 9, 14 and 42).

Completely open: Head (no gates).

Reading it step by step:

1. Type. The Sacral is white, so this is not a Generator. The Solar Plexus, a motor, reaches the Throat through channel 12-22 (Openness), the highlighted line. Motor to Throat with no Sacral makes a Manifestor.
2. Authority. The Spleen is defined too, but the Solar Plexus outranks it. Defined Solar Plexus means Emotional authority, every time.
3. What runs steady. Heart, Spleen, Solar Plexus and Root are joined by 37-40 (Community), 19-49 (Synthesis) and 18-58 (Judgment): a consistent will, instinct, emotional rhythm and relationship with pressure.
4. Where they take in the room. The undefined Sacral means borrowed work energy, the undefined G means direction comes through places and people, and the completely open Head means other people's questions can land as their own.

The birth time matters. The engine's hour-by-hour check for the same date shows a Manifestor at 16 of the 24 hourly times on 30 May 1981 and a Projector at the other 8. The switch comes at 07:01, only 54 minutes before this example's 07:55: at 06:55 the same person would chart as a Projector, because channel 12-22 isn't complete yet and the Throat is still white. Across that one day the set of defined centers takes four different shapes, while Authority stays Emotional throughout. A center set that shifts during the day is the norm, not the exception: in a wider simulation of 500 random dates, it stayed the same all day on only about 1 in 4 (24.0%, 10-minute check, September 2026). The guide to charts without a birth time explains what you can and can't trust in that case.

Where to start with your own chart

This order gets you something usable fastest.

1. The center behind your authority. Check the Solar Plexus first. If it's defined, that's your authority. If not, look at the Sacral, then the Spleen, then the Heart. The authority guide covers the full order.
2. Your white motors. An undefined or open Sacral, Heart or Root is where you're most likely to run on borrowed energy or borrowed pressure.
3. Your completely open centers. No active gates means no fixed theme at all, so this is where outside influence is strongest.
4. Head and Ajna last. In Human Design the mind isn't where decisions are meant to come from, so these can wait.

The quickest way to see all nine is the free chart calculator. It shows which centers are defined and which are white, with every active gate marked on the bodygraph, so you can tell an undefined center (some gates lit) from a completely open one (none). It also lists your channels and all 26 activations, runs in the browser and doesn't need an email. The free Type Test is a nine-question estimate of your Type; it can't show centers, because centers come only from a birth date, time and place.

What people ask about the nine centers

What is the difference between an undefined and an open center?

Both are white on the chart. An undefined center has at least one active gate, so it carries a fixed theme without steady energy. A completely open center has no active gates at all. In practice both take in and amplify other people's energy; the open one has no fixed theme of its own to hold on to.

How do the 9 centers relate to the 7 chakras?

Human Design uses nine centers where chakra systems use seven. In Ra Uru Hu's teaching, humans shifted from a seven-centered to a nine-centered design in 1781, the year Uranus was discovered; the Jovian Archive dictionary ties the change to that date in its "Uranian Life Cycle" entry. The centers are read as parts of a decision-making map, not as chakras.

Try this with your own open centers

Defined centers are where you're steady; white centers are where you learn from, and sometimes get lost in, the people around you.

One thing to try: find a white center on your chart (undefined or open) that matches a feeling you get a lot (urgency for the Root, proving yourself for the Heart, emotional heat for the Solar Plexus). Write down the next three times it shows up and who you were with.

When you want your centers read together with your Type, Authority, Profile and channels for your exact chart, get your personalized Human Design Blueprint.

Sources. Jovian Archive, The Nine Centers of the BodyGraph and the Human Design Dictionary (both checked 2026-09-28). Simulated shares: YourHumanDesign chart engine, 4,000 random UTC birth moments (1950–2009, seed 20260927) and 500 random dates for the whole-day check (seed 20260929, 10-minute steps), run 2026-09-28.

How we made this: drafted with AI assistance, fact-checked against the Jovian Archive centers page and dictionary linked above, extended with YourHumanDesign engine data (simulated births, run 2026-09-28) and engine-drawn diagrams, and edited by YourHumanDesign Editorial on 2026-09-28. Interpretation for self-reflection, not medical or mental-health advice.