Enter Your Clinical Parameters

Age (Years)

yrs

Biological Sex

Male Female

Height (Centimeters)

E.g., 5 ft 6 in ≈ 168 cm | 5 ft 10 in ≈ 178 cm

Your Measured Peak Flow (Optional)

L/min

Leave blank if testing before blowing into a peak flow meter

Clinical Assessment Result

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units

Enter your details and click calculate to view clinical interpretation.

Physician's Guidance

Evaluation guided by Maruti Hospital clinical guidelines.

Book Doctor Consultation Call: 84896 96111

Medical Oversight

Dr. K.C. Saravanakumar, MD, DTCD

Senior Consultant Pulmonologist & Chest Physician — Maruti Hospital

"Early screening and objective metrics help prevent chronic disease complications before symptoms manifest."

Consult Dr. K.C. Saravanakumar, MD, DTCD

Clinical Formula & Evidence

Peak Expiratory Flow Rate (PEFR) measures the maximum speed of air expelled during a forced expiration. Normal values are derived from standard pulmonary reference equations based on height, age, and sex. The traffic light action zones (Green 80-100%, Yellow 50-79%, Red <50%) guide asthma self-management.

Clinical Reference Stages

Green Zone (80% – 100%) Good Control. No coughing, wheezing, or chest tightness. Sleeping through the night. Continue daily maintenance inhalers as prescribed.
Yellow Zone (50% – 79%) Caution / Flare-Up. Mild-to-moderate symptoms, nighttime waking. Use quick-relief bronchodilator inhaler and monitor response closely.
Red Zone (< 50%) Medical Alert / Emergency. Severe shortness of breath, inability to speak full sentences. Use reliever immediately and visit Maruti 24/7 Emergency without delay.

Related Clinical Calculators

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Peak Expiratory Flow (PEFR) & Asthma Action Zones

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Clinical Assessment Result