# Residual Volume Calculator

Determines the air that remains in the lungs after maximal expiration.

The Residual Volume (RV) is one of the four pulmonary volume and defines the volume of gas remaining in the lung after a person has exhaled to maximum capacity.

The RV cannot be determined directly using spirometry and so is either estimated or more advanced techniques are employed to determine this parameter.

`Residual Volume (RV) = Functional Residual Capacity (FRC) – Expiratory Reserve Volume (ERV)`

OR

`Residual Volume (RV) = Total Lung Capacity (TLC) – Vital Capacity (VC)`

 Parameter Normal Low Normal High Residual volume (RV) 1.0 L 2.0 L Functional residual capacity (FRC) 2.0 L 4.0 L Expiratory reserve volume (ERV) 1.0 L 2.0 L Total lung capacity (TLC) 5.0 L 7.0 L Vital capacity (VC) 4.0 L 5.0 L

Functional Residual Capacity (FRC)
Expiratory Reserve Volume (ERV)
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Total Lung Capacity (TLC)
Vital Capacity (VC)
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## Send Us Your Feedback

Steps on how to print your input & results:

1. Fill in the calculator/tool with your values and/or your answer choices and press Calculate.

2. Then you can click on the Print button to open a PDF in a separate window with the inputs and results. You can further save the PDF or print it.

Please note that once you have closed the PDF you need to click on the Calculate button before you try opening it again, otherwise the input and/or results may not appear in the pdf.

## Residual Volume Explained

The Residual Volume (RV) is one of the four pulmonary volume and defines the volume of gas remaining in the lung after a person has exhaled to maximum capacity.

The RV cannot be determined directly using spirometry and so is either estimated or more advanced techniques are employed to determine this parameter:

• Gas dilution tests (e.g. helium dilution test, nitrogen washout);
• Body Plethysmography.

Reference values for RV are between 1.0 and 2.0 L but these values are dependent factors such as age, gender, height, weight (BMI increases correlate with RV increases), and physical activity levels.

The function of the residual volume is to keep the alveoli open even after maximum expiration. In healthy individuals, the RV allows for continual gas exchange to occur between breaths.

### Formulas

• `Residual volume (RV) = Functional Residual Capacity – Expiratory Reserve Volume`
• `Residual volume (RV) = Total Lung Capacity – Vital Capacity`

### Normal Reference Ranges

 Parameter Normal Low Normal High Residual volume (RV) 1.0 L 2.0 L Functional residual capacity (FRC) 2.0 L 4.0 L Expiratory reserve volume (ERV) 1.0 L 2.0 L Total lung capacity (TLC) 5.0 L 7.0 L Vital capacity (VC) 4.0 L 5.0 L

RV is a measure of the function of the respiratory system and is either increased or decreased, depending on the mechanism of the pulmonary condition.

In obstructive lung diseases (e.g. asthma, COPD, bronchiectasis), which are characterized by airway inflammation, easily collapsible airways and expiratory flow obstruction, TLC, FRC and RV are increased.

In restrictive lung diseases (e.g. pulmonary fibrosis, sarcoidosis), which are characterized by restricted expansion, decreased lung volumes and inadequate ventilation, TLC, FRC and RV are decreased.

## References

Mortola JP. How to breathe? Respiratory mechanics and breathing pattern. Respir Physiol Neurobiol. 2019; 261:48-54.

Krol K, Morgan MA, Khurana S. Pulmonary Function Testing and Cardiopulmonary Exercise Testing: An Overview. Med. Clin. North Am. 2019; 103(3):565-576.

Kishaba T. Acute Exacerbation of Idiopathic Pulmonary Fibrosis. Medicina (Kaunas). 2019; 55(3).

Lumb AB. Pre-operative respiratory optimisation: an expert review. Anaesthesia. 2019; 74 Suppl 1:43-48.

Specialty: Pulmonology

System: Respiratory

Abbreviation: RV

Article By: Denise Nedea

Published On: June 15, 2020

Last Checked: June 15, 2020

Next Review: June 15, 2025