Plateletcrit (PCT) measures the total volume of platelets in your blood as a percentage of the total blood volume. It reflects how much space platelets occupy in your bloodstream, similar to how hematocrit measures red blood cell volume.

Formula
Where:
- Platelet Count: Number of platelets per microliter (µL) of blood (e.g., 250 × 10³/µL = 250,000 platelets/µL).
- MPV: Mean Platelet Volume (average size of platelets in femtoliters, fL).
Step-by-Step Calculation
- Get your lab results:
- Platelet count (e.g., 300 × 10³/µL).
- MPV (e.g., 9 fL).
- Multiply Platelet Count × MPV:
- Divide by 10,000:
Example Result:
- PCT = 0.27% (Normal range: 0.22–0.24%).
🧮 Plateletcrit (PCT) Calculator
📐 Formula:
Normal Range
| Group | PCT Range |
|---|---|
| Adults | 0.22–0.24% |
| Newborns | Slightly higher (up to 0.28%) |
Why PCT Matters
- High PCT (>0.24%):
- Indicates increased platelet production (e.g., infection, inflammation, blood loss).
- Low PCT (<0.22%):
- Suggests low platelet production (e.g., bone marrow disorders, chemotherapy).
How to Use a PCT Calculator
- Enter Platelet Count (from your CBC report).
- Enter MPV (from CBC).
- Click Calculate – Done!
Limitations
- Requires accurate MPV (results vary between labs).
- Rarely used alone – combine with platelet count and MPV for diagnosis.
Quick Reference Table
| Parameter | Value | Meaning |
|---|---|---|
| Platelet Count | 150–450 × 10³/µL | Normal range |
| MPV | 7.5–12 fL | Platelet size |
| High PCT | >0.24% | Inflammation, thrombosis |
| Low PCT | <0.22% | Bone marrow failure |
Key Takeaway
PCT helps assess platelet activity but is not a standalone test. Always interpret it with platelet count, MPV, and clinical symptoms.







