COPD diagnosis (outside this tool) requires post-bronchodilator FEV₁/FVC <0.7 in an appropriate clinical context.

This calculator applies GOLD spirometric grades and GOLD 2023+ ABE symptom/exacerbation groups.

GOLD grade	Description	Post-bronchodilator FEV₁ % predicted
1	Mild	≥80%
2	Moderate	50% to <80%
3	Severe	30% to <50%
4	Very severe	<30%

Group	Symptoms	Exacerbation history (past 12 months)
A	Fewer symptoms (mMRC 0–1 or CAT <10)	0–1 moderate exacerbations and none leading to hospital admission
B	More symptoms (mMRC ≥2 or CAT ≥10)	0–1 moderate exacerbations and none leading to hospital admission
E	Any symptom level	≥2 moderate exacerbations or ≥1 exacerbation requiring hospital admission

Global Initiative for Obstructive Lung Disease (GOLD) Criteria for COPD