Vital capacity is reduced in restrictive lung diseases, neuromuscular weakness and after chest surgery. In neuromuscular conditions such as Guillain–Barré syndrome, a vital capacity below about 20 mL/kg warns of respiratory failure.
How to use the Vital Capacity Calculator
- Sex
- Age
- Height
- Measured vital capacity (optional)
- Weight
Results update as you type, and every field accepts the units shown in its menu.
How it works
Enter sex, age and height, plus measured vital capacity and weight if available.
Inputs explained
| Field | What to enter |
|---|---|
| Sex | Choose one: Male, Female |
| Age | In years |
| Height | Units: cm, in, m, ft, mm |
| Measured vital capacity (optional) | In L |
| Weight | Units: kg, lb, st, g |
Example values
How the main result changes when Age changes and everything else stays at the example values above:
| Age (years) | Predicted vital capacity (L) |
|---|---|
| 20 | 4.44 |
| 30 | 4.25 |
| 40 | 4.05 |
| 50 | 3.86 |
| 60 | 3.66 |
| 80 | 3.27 |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
Men: VC (mL) = (27.63 − 0.112 × age) × height (cm)
Women: VC (mL) = (21.78 − 0.101 × age) × height (cm)
Worked example
Inputs — Sex: Male; Age: 40 years; Height: 175 cm; Measured vital capacity (optional): 0 L; Weight: 75 kg.
Results — Predicted vital capacity = 4.05 L; Measured as % of predicted = 100 %; Measured vital capacity per kg = 54 mL/kg.
Key terms
- VC
- Vital capacity.
Frequently asked questions
What is a normal vital capacity?
About 4–5 litres in adult men and 3–4 litres in women.
Why is mL/kg important?
In neuromuscular weakness, below 20 mL/kg is a warning sign for ventilation.
How is vital capacity measured?
With a spirometer, slowly (SVC) or forcefully (FVC).
Sources
- Baldwin ED et al. Pulmonary insufficiency: physiological classification. Medicine, 1948