Volume per breath
Use the measured tidal volume.
Minute Ventilation
Total ventilation. Alveolar contribution. One clear breakdown.
Breaths per minute
Use the observed respiratory rate.
Dead-space context
Assumptions must stay visible.
MINUTE VENTILATION · VE
L/min
— mL/min
Estimated alveolar · VA—
Dead-space ventilation—
Enter measurements to calculate.
Where each minute goes
Alveolar —Dead space —
Adult resting context: approximately 5–8 L/min.Context only; not a diagnostic range or treatment target.
Ventilation is not oxygenation
Total air moved does not measure blood oxygen or CO2 clearance.
Physiological dead space may exceed an anatomical estimate.
Illustration only · not measured gas exchange
Same total. Different alveolar estimate.
| Breathing pattern | VE (total) | Estimated VA |
|---|---|---|
| 500 mL × 14/min | 7.0 L/min | 4.9 L/min |
| 250 mL × 28/min | 7.0 L/min | 2.8 L/min |
Teaching examples with VD fixed at 150 mL. Not a recommendation to alter breathing.
VE = VT × RRVA = (VT − VD) × RR
Convert mL/min to L/min by dividing by 1,000.
Calculation & limitations
Total ventilation includes both gas-exchanging and dead-space ventilation. VA here is an estimate under the entered VD model. An anatomical estimate does not capture increased alveolar or apparatus dead space. A reported physiological VD may be used only when appropriate to the measurement context.
VT and RR must be positive. VD must be nonnegative and no greater than VT. An unavailable VD leaves VA and the split uncalculated. A VD equal to VT produces a modelled VA of zero; this is not a diagnosis. Measurements, clinical context and blood-gas assessment remain essential.
The resting context band is illustrative for adults, varies between sources and individuals, and is not used to grade results. This page does not assess ventilation adequacy, hypoxia or ventilator settings.
Frequently asked questions
How is minute ventilation calculated?
Multiply tidal volume in mL by respiratory rate in breaths/min, then divide by 1,000 for L/min. For example, 500 × 14 = 7,000 mL/min = 7.0 L/min.
Is 150 mL appropriate for everyone?
No. It is a rough adult anatomical teaching assumption, not an individual measurement. Physiological dead space also includes alveolar dead space and can differ substantially with disease or equipment. Choose Not available if VD is unknown.
Does 7 L/min mean ventilation is adequate?
No. Total ventilation alone cannot establish effective CO2 clearance or oxygenation. Dead space, metabolic demand, blood gases and the clinical situation matter.
Can I use this to adjust a ventilator?
No. This educational tool does not prescribe ventilator settings or treatment. A qualified clinician must interpret measured respiratory data in the full clinical context.
Sources & References
OpenStaxOpenStaxRespiratory physiologyOverview of ventilation, dead space and gas exchange.NCBINCBI BookshelfTidal volume & dead spaceStatPearls respiratory physiology reference.MerckMerck ManualVentilation and clinical contextClinical overview of ventilation and related physiology.
References are provided for educational use. No institutional endorsement, approval or accreditation is claimed.
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Total ventilation. Alveolar contribution. One clear breakdown.