PASI Psoriasis Score Calculator

Calculate your PASI score by rating redness, thickness, and scaling across four body regions to quantify psoriasis severity.

Use the PASI Psoriasis Score Calculator

Rate each body region on three severity components (0 = none, 1 = slight, 2 = moderate, 3 = severe, 4 = very severe) and select the area score that best matches the percentage of that region affected.

1 Head & Neck (weight 0.1)

0
0 None1 Slight2 Mod.3 Severe4 V. Severe
0
0 None1 Slight2 Mod.3 Severe4 V. Severe
0
0 None1 Slight2 Mod.3 Severe4 V. Severe

2 Upper Limbs (Arms) (weight 0.2)

0
0 None1 Slight2 Mod.3 Severe4 V. Severe
0
0 None1 Slight2 Mod.3 Severe4 V. Severe
0
0 None1 Slight2 Mod.3 Severe4 V. Severe

3 Trunk (weight 0.3)

0
0 None1 Slight2 Mod.3 Severe4 V. Severe
0
0 None1 Slight2 Mod.3 Severe4 V. Severe
0
0 None1 Slight2 Mod.3 Severe4 V. Severe

4 Lower Limbs (Legs) (weight 0.4)

0
0 None1 Slight2 Mod.3 Severe4 V. Severe
0
0 None1 Slight2 Mod.3 Severe4 V. Severe
0
0 None1 Slight2 Mod.3 Severe4 V. Severe

PASI Score Result

0.0
out of 72.0
Clear
No active psoriasis detected
Region Breakdown
Head & Neck 0.00
Upper Limbs (Arms) 0.00
Trunk 0.00
Lower Limbs (Legs) 0.00
Severity Scale
Clear0
Almost clear0.1 – 1
Mild1.1 – 7
Moderate7.1 – 12
Severe12.1 – 20
Very severe> 20

For informational purposes only. Consult a dermatologist for clinical assessment and treatment decisions.

Summary

Calculate your PASI score by rating redness, thickness, and scaling across four body regions to quantify psoriasis severity.

How it works

  1. Rate erythema (redness), induration (thickness), and desquamation (scaling) 0–4 for each body region.
  2. Estimate the percentage of that region covered by psoriasis and select the matching area score (0–6).
  3. The calculator multiplies severity scores by area score and a region weight for each of the four regions.
  4. All four region subtotals are summed to produce the total PASI score (0–72).
  5. Use the color-coded severity band to interpret your result.

Use cases

  • Track psoriasis severity before and after starting a new treatment.
  • Document PASI scores for dermatology clinic visits.
  • Screen eligibility for biologic or systemic therapy (PASI >= 10 often required).
  • Monitor response to phototherapy over multiple sessions.
  • Research and clinical trial data collection.
  • Patient self-assessment between appointments.

Frequently Asked Questions

Last updated: 2026-09-30 · Reviewed by Nham Vu