Canonical: https://echosuite.app/guides/effusion-size/

# Pericardial effusion size measurement guide and calculator

Explore the pericardial effusion size tool, its measurement acquisition teaching and its source context.

Created by [Mohammed Kamareddine, MD](https://echosuite.app/about/) · [Sources & educational scope](https://echosuite.app/about/)

[Open interactive calculator →](https://echosuite.app/calculators/#effusion-size)

## Method

Maximum echo-free separation at end-diastole (mm)

Use the measurement units shown below. Some fields apply only to a selected method or condition; follow the interactive tool’s method choices. The interactive tool keeps missing measurements incomplete and provides its method-specific results and reference context.

## Measurements and acquisition

### Maximum end-diastolic separation  mm

Enter the measured value in the displayed unit

- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.

## Sources and method context

European Society of Cardiology · 2025 · 2025 ESC Guidelines for the Management of Myocarditis and Pericarditis · Section 5.5 and Table 10 · Classification of pericardial effusion

[Primary reference](https://academic.oup.com/eurheartj/article/46/40/3952/8234483)

- Method and interpretation · Section 5.5 and Table 10 · Classification of pericardial effusion

Largest end-diastolic echo-free separation: small <10 mm, moderate 10–20 mm, large >20 mm; evaluate distribution and hemodynamic findings separately.

Catalogue review status: Exact guideline locator mapped · clinical sign-off pending

These pages describe the educational tool. Interpret measurements with the complete clinical context and the method’s acquisition limitations.

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