10-20 Electrode Placement Guide¶
Finding the right spot for your electrodes is easier than it looks! This guide will help you locate common training sites using simple landmarks and measurements.
📍 Quick Jump to Location¶
Click to jump to detailed instructions:
Midline (Center)¶
Sensorimotor (Most Common)¶
Frontal¶
Parietal¶
Temporal¶
Occipital¶
References¶
A1 (Left Ear) • A2 (Right Ear)
Not sure where to start? See Most Common Sites below.
🎯 Most Common Sites¶
These are the locations you'll use most often:
| Site | Location | Used For |
|---|---|---|
| C4 | Right side, above ear | Most common - calm focus, regulation |
| Cz | Top center of head | Core regulation, centering |
| C3 | Left side, above ear | Activation, energy |
| Fz | Forehead center | Relaxation, downshift |
| Pz | Back of head center | Processing, relaxation |
Ear references (A1/A2): Clip electrodes to earlobes
📍 Finding Anatomical Landmarks¶
Before you can find electrode positions, you need three key landmarks:
1. Nasion (Bridge of Nose)¶
Where: The dip at the bridge of your nose, between your eyebrows
How to find: 1. Place finger at top of nose 2. Feel for the indentation where nose meets forehead 3. This is your nasion
2. Inion (Back Bump)¶
Where: The bony bump at the back of your skull, just above your neck
How to find: 1. Run finger up from neck along the centerline 2. Feel for a distinct bump 3. This is your inion
3. Preauricular Notch (In Front of Ear)¶
Where: The point where the front of your ear meets your face
How to find: 1. Open and close your jaw 2. Touch in front of your ear while doing this 3. Feel for the small dip/groove 4. This is your preauricular notch (or "ear notch")
🔎 The Rope Method¶
The easiest way to find electrode positions is using the "rope method" - two pieces of string with knots marking key positions.
Rope 1: Front to Back (Nasion to Inion)¶
You'll need: - String or ribbon - Ruler or tape measure - Marker or pen
Steps:
- Measure from nasion (bridge of nose) over the top of your head to inion (back bump)
- Mark these positions on your string:
- 10% from nasion = Fpz (forehead)
- 30% from nasion = Fz (front center)
- 50% from nasion = Cz (top center - vertex)
- 70% from nasion = Pz (back center)
- 90% from nasion = Oz (very back)
Example: If your measurement is 40 cm: - Fpz = 4 cm from nasion - Fz = 12 cm from nasion - Cz = 20 cm from nasion (halfway!) - Pz = 28 cm from nasion - Oz = 36 cm from nasion
Rope 2: Side to Side (Ear to Ear)¶
- Measure from left preauricular notch over Cz to right preauricular notch
- Mark 7 positions (symmetrical):
- Preauricular (left ear)
- T3 (left temporal)
- C3 (left central)
- Cz (center - same as Rope 1)
- C4 (right central)
- T4 (right temporal)
- Preauricular (right ear)
📌 Common Electrode Sites¶
C4 (Right Central) - MOST COMMON¶
Your most-used site!
Location: Right side of head, above and slightly forward of the ear
How to find: 1. Use your ear-to-ear rope 2. Find Cz (top center) 3. C4 is about 20% of the ear-to-ear distance to the RIGHT of Cz 4. Should be about 1-1.5 inches above your ear
Quick check: Use side-to-side rope with Cz in center
Why we use it: Calm focus, emotional regulation, sleep
Tips: - Part hair to expose scalp - Should feel above your ear, not next to it - Symmetry matters - C3 and C4 should be equal distance from Cz
Cz (Vertex/Top Center)¶
Location: The absolute top-center of your head
How to find: 1. Use your front-to-back rope 2. Cz = 50% from nasion (halfway point) 3. Verify with ear-to-ear measurement - should also be halfway
Alternative: Where the two ropes cross!
Why we use it: Core regulation, grounding
Tips: - This is usually the highest point on your head - Should be directly in line with nasion and inion - Should be equal distance from both ears
C3 (Left Central)¶
Location: Left side of head, mirror of C4
How to find: 1. Find Cz first 2. C3 is same distance LEFT of Cz as C4 is RIGHT 3. About 1-1.5 inches above left ear
Why we use it: Activation, energy, verbal processing
Tips: - Should be symmetrical with C4 - Verify both are on the same line (coronal plane)
Fz (Frontal Center)¶
Location: Center of forehead
How to find: 1. Use your front-to-back rope 2. Fz = 30% from nasion 3. On the centerline of your forehead
Why we use it: Relaxation, anxiety reduction, "downshift"
Tips: - Above eyebrows, on midline - Not too far back (that would be closer to Cz) - Usually about 2-3 inches above eyebrows
Pz (Parietal Center)¶
Location: Back-center of head
How to find: 1. Use your front-to-back rope 2. Pz = 70% from nasion 3. On the centerline at the back
Quick tip: Feel for a slight flat spot - Pz is often there
Why we use it: Processing, relaxation, integration
Tips: - There's often a slight indentation or flat area here - Should be on the midline - About 70% back from nasion
A1 and A2 (Ear References)¶
Location: Earlobes
How to attach: 1. Use spring clip electrodes 2. Clip to fleshy part of earlobe 3. A1 = left ear, A2 = right ear
Why we use them: Reference electrodes for most training
Tips: - Firm but not painful - Can also clip behind ear at preauricular notch for QEEG - Add a tiny bit of paste to the clip for better contact
📌 Additional Electrode Sites¶
Fpz (Frontal Pole)¶
Location: Very front center of forehead
How to find: 1. Use front-to-back rope 2. Fpz = 10% from nasion 3. On centerline, low on forehead
Why we use it: Rare in training, common in QEEG
Tips: - Just above eyebrows on midline - Feel for slight indentation
Fp1 & Fp2 (Frontal Poles)¶
Location: Front corners of forehead, above outer eyebrows
How to find: 1. From Fpz, measure laterally (sideways) 2. Fp1 = left, Fp2 = right 3. Above outer edge of eyebrows
Why we use it: Sometimes for frontal training, QEEG
F3 & F4 (Frontal Corners)¶
Location: Front-side of head, above Fz level
How to find: 1. Find Fz first (30% from nasion) 2. Measure sideways similar to how you find C3/C4 3. F3 = left, F4 = right
Why we use it: Beta training, activation, attention
Tips: - Should be symmetrical - Forward of C3/C4 line
F7 & F8 (Frontal Temporal)¶
Location: Temples, in front of ears
How to find: 1. Find the "hat line" (ear to ear over top) 2. F7/F8 are on this line 3. Forward of ears, at soft/tender depression
Why we use it: Emotional processing, temporal lobe training
Tips: - Often a soft spot, slightly tender - Can feel your jaw move when you open/close mouth
T3 & T4 (Mid Temporal)¶
Location: Directly above ears
How to find: 1. Use side-to-side rope (ear to ear) 2. T3 = left, T4 = right 3. Directly above ear canal
Why we use it: Temporal regulation, emotional processing
Tips: - Right above the ear - On the coronal plane (ear-to-ear line)
T5 & T6 (Posterior Temporal)¶
Location: Back-side of head, behind ears
How to find: 1. Halfway between T3 and O1 (or T4 and O2) 2. T5 = left, T6 = right 3. On the "hat line"
Alternative method: 1. Feel along hat line from ear backward 2. Find bony ridge 3. That's usually T5/T6
Why we use it: Often trained together with T3/T4, parietal work
Tips: - Feel for bony prominence - Back corner of head
P3 & P4 (Parietal Corners)¶
Location: Back-upper corners of head
How to find: 1. Find Pz first (70% from nasion) 2. Measure laterally like C3/C4 3. P3 = left, P4 = right
Why we use it: Processing, integration, relaxation
Tips: - Behind C3/C4 line - Should be symmetrical
POz (Parietal-Occipital)¶
Location: Between Pz and Oz on midline
How to find: 1. Find Pz (70%) and Oz (90%) 2. POz is midway between them (~80%) 3. Often a slight flat area
Why we use it: Alpha training, processing, relaxation
Tips: - Feel for flat spot - On the "PO line" (between parietal and occipital)
PO3 & PO4 (Advanced)¶
Location: Sides, between parietal and occipital
How to find: 1. Find POz first 2. Measure laterally 3. PO3 = left, PO4 = right
Why we use it: Advanced protocols, less common
Tips: - Symmetry more important than precision - Back-side of head
O1 & O2 (Occipital Sides)¶
Location: Very back of head, sides
How to find: 1. Find Oz (90% from nasion, very back) 2. Measure laterally 3. O1 = left, O2 = right
Why we use it: Visual processing, alpha training, QEEG
Tips: - Very back of skull - Where skull curves down toward neck
Oz (Occipital)¶
Location: Very back center of head
How to find: 1. Use front-to-back rope 2. Oz = 90% from nasion (almost at inion) 3. On midline, where skull curves down
Why we use it: Visual cortex, alpha, QEEG
Tips: - Just above inion bump - Where head starts curving down toward neck
🎨 Applying Electrodes¶
Step-by-Step¶
- Prep the site:
- Part hair to expose scalp
-
Wipe with alcohol swab or NuPrep (optional but helps)
-
Add paste:
- Small pea-sized amount to electrode
-
Too much = messy, too little = poor contact
-
Place electrode:
- Press firmly against scalp
- Wiggle slightly to ensure good contact
-
Hair should be parted around it
-
Check signal:
- Before starting training, verify signal quality
- Should see thin, jagged lines (not thick fuzzy ones)
See: Signal Quality Troubleshooting if signal looks bad
🔍 Symmetry Matters for Bilateral Placements¶
Symmetry is critical when using paired electrodes (both sides of the head):
Bilateral Protocols Include:¶
- C3/C4 (left and right sensorimotor)
- F3/F4, F7/F8 (frontal bilateral)
- T3/T4, T5/T6 (temporal bilateral)
- P3/P4 (parietal bilateral)
- O1/O2 (occipital bilateral)
For Bilateral Placements:¶
✅ Do: - Measure from same landmarks on both sides - Verify equal distance from centerline - Check that sites are on same line (left-right plane) - Within 1 cm accuracy on each side
❌ Don't: - Eyeball it - measure! - Assume hair parts indicate correct position - Place one higher/forward/back than the other
For single-site protocols (like C4-A1 or Fz-Pz): Symmetry doesn't apply - just get within 1 cm of the target location.
When in doubt: Take a photo and send to your coach in Slack!
📸 Taking Photos for Your Coach¶
If you're unsure about a placement:
- Part hair at the site
- Place electrode
- Take photo from angle that shows:
- The electrode position
- Nearby landmarks (ear, centerline, etc.)
- Overall head orientation
- Send to Slack with: "Does this look right for C4?"
Coaches can usually tell immediately if it's correct or needs adjustment.
🤔 Common Questions¶
How precise do I need to be?¶
Within 1 cm (about half an inch) of the target location. Closer is better, but 1 cm is acceptable.
For bilateral placements (like C3/C4, T5/T6, F7/F8): Symmetry matters - both sides should be equal distance from centerline and positioned on the same plane.
What if I can't find a landmark?¶
Some people have less pronounced features. Use the rope method and measurements - they're more reliable than feeling for bumps.
Can I use the same positions every session?¶
Yes! In fact, consistency is good. Once you've found C4, you can use the same general area each time.
What about hair?¶
Part it! You need good scalp contact. Use a comb or your fingers to part hair around the electrode site.
My head shape is unusual - will this still work?¶
Yes. The 10-20 system scales to any head size/shape because it uses percentages, not fixed measurements.
🆘 When to Contact Your Coach¶
Before starting a session if: - ❌ You can't find a landmark - ❌ Measurements don't make sense - ❌ Electrode won't stay in place - ❌ You're not sure if you're in the right spot
Don't guess! A quick Slack message with a photo can save you time and ensure effective training.
📚 Learn More¶
Related Guides¶
- Your Equipment - What's in your kit
- Finding Locations (Rope Method) - Detailed rope instructions
- Electrode Care - Cleaning and maintenance
- Signal Quality Help - Troubleshooting
Video Resources¶
Check your Slack channel for links to: - Rope-making demonstration - Placement verification videos - Virtual Intensive session recordings
🎯 Quick Placement Checklist¶
Before each session:
- Locate landmarks (nasion, inion, ear notches)
- Use rope to find position OR measure from known landmarks
- Part hair at electrode site
- Clean skin (optional but recommended)
- Apply small amount of paste to electrode
- Press electrode firmly to scalp
- Verify symmetry (if bilateral placement)
- Check signal quality before starting
- Take photo if unsure (send to Slack!)
Remember: Practice makes perfect! After a few sessions, you'll find your common sites quickly and confidently. And your coach is always available in Slack to help! 🧠✨
This guide compiled from Peak Brain's internal placement sheets and 10 years of remote training experience. For questions, contact your coach.