Rapid Shallow Breathing Index (RSBI = f / VT) & Mechanical Ventilation Tidal Volume Calculator

Compute RSBI (f / VT_L) for spontaneous breathing trials and 6 mL/kg lung-protective VT.

Rapid Shallow Breathing Index (RSBI)
57.89 breaths/min/L
Minute Ventilation (VE = RR × VT) 8.36 L/min
ARDSNet 6 mL/kg Protective VT 408 mL
Current VT per kg PBW 5.59 mL/kg
Inputs
⚡ Scenarios:
breaths/min
Spontaneous breathing frequency (breaths/min).
mL
Spontaneous exhaled tidal volume in mL.
kg
ARDSNet Predicted Body Weight (PBW) in kg for 6–8 mL/kg target.
Results & Graph
Rapid Shallow Breathing Index (RSBI)
57.89 breaths/min/L
Minute Ventilation (VE = RR × VT)
8.36 L/min
ARDSNet 6 mL/kg Protective VT
408 mL
Current VT per kg PBW
5.59 mL/kg

Rapid Shallow Breathing Index (RSBI)

Graph 1 • RSBI & Ideal Tidal Volume • Domain Architecture & Live Telemetry Maps Spontaneous Respiratory Rate, Spontaneous Tidal Volume Ml, Predicted Body Weight Kg through RSBI & Ideal Tidal Volume Formula.
RSBI & Ideal Tidal Volume • Clinical & Physiological Reference Scale Low / Baseline Target / Reference Elevated / Watch High / Action Rapid Shallow Breathing Index (RSBI): 57.89 breaths/min/L Minute Ventilation (VE = R 8.36 L/min ARDSNet 6 mL/kg Protective 408 mL Current VT per kg PBW 5.59 mL/kg
Graph 2 • Rapid Shallow Breathing Index (RSBI) Across Spontaneous Respiratory Rate Sweep (40% → 160%) Evaluates RSBI = RespiratoryRate (breaths/min) / TidalVolume (Liters); MinuteVen across 7 operating points (current input highlighted).
0 breath 50.95 breath 101.9 breath 23.16 8.80 34.74 13.20 46.32 17.60 57.89 22 69.47 26.40 81.05 30.80 92.63 35.20
Graph 3 • Joint Sensitivity: Spontaneous Respiratory Rate × Spontaneous Tidal Volume Ml Compares Rapid Shallow Breathing Index (RSBI) when Spontaneous Tidal Volume Ml is shifted +25% (solid) vs. −25% (dashed).
0 breath 55.19 breath 110.4 breath --- Spontaneous Tidal Volume Ml @ 75% 32.42 -30% 39.37 -15% 46.32 +0% 53.26 +15% 60.21 +30%
Summary: At 22 breaths/min and 380 mL (0.38 L) tidal volume, RSBI is 57.9 breaths/min/L (Favorable for weaning <105); ARDSNet 6 mL/kg target is 408 mL.
Summary: At 22 breaths/min and 380 mL (0.38 L) tidal volume, RSBI is 57.9 breaths/min/L (Favorable for weaning <105); ARDSNet 6 mL/kg target is 408 mL.
⚡ Send result to: BMI →Calorie & TDEE →Pace, 1RM & HR Zones →
Interactive chart & math engine powered by CalculatorGraph

Formula & Mathematical Methodology: RSBI & Ideal Tidal Volume Formula

RSBI = RespiratoryRate (breaths/min) / TidalVolume (Liters)
MinuteVentilation (VE) = RR × VTL
RSBI = RespiratoryRate (breaths/min) / TidalVolume (Liters); MinuteVentilation (VE) = RR × VT_L
  • spontaneousRespiratoryRate: Spontaneous Respiratory Rate (breaths/min)
  • spontaneousTidalVolumeMl: Spontaneous Tidal Volume Ml (mL)
  • predictedBodyWeightKg: Predicted Body Weight Kg (kg)

Rounding: Clinical scores round to statutory integer or decimal precision; physiological metrics round to 2 decimal places.

Worked Example: Clinical / Physiology Scenario: RSBI & Ideal Tidal Volume

Compute RSBI (f / VT_L) for spontaneous breathing trials and 6 mL/kg lung-protective VT.

  1. Enter lab values, anthropometric measurements, or performance test metrics.
  2. Evaluate the reference equation: RSBI = RespiratoryRate (breaths/min) / TidalVolume (Liters); MinuteVentilation (VE) = RR × VT_L.
  3. Inspect the primary classification, supporting indices, and 3 SVG charts.
Result: Computes RSBI & Ideal Tidal Volume via RSBI = RespiratoryRate (breaths/min) / TidalVolume (Liters); MinuteVentilation (VE) = RR × VT_L.

Frequently Asked Questions

How does the Rapid Shallow Breathing Index (RSBI = f / VT) & Mechanical Ventilation Tidal Volume Calculator compute its result?

It evaluates RSBI = RespiratoryRate (breaths/min) / TidalVolume (Liters); MinuteVentilation (VE) = RR × VT_L directly in your browser and updates three custom SVG visualizations in real time.

Can I use Goal Seek to solve backwards for a target lab value or pace?

Yes. Click "🎯 Goal Seek" in the results toolbar to solve backwards for any numeric input parameter.

Are my health and biometric inputs kept private?

Yes. All calculations run 100% locally on your device with zero external transmission.

Health & Fitness · Pulmonary, Critical Care & Acid-Base

Rapid Shallow Breathing Index (RSBI = f / VT) & Mechanical Ventilation Tidal Volume Calculator: inputs, method, and how to read the result

Compute RSBI (f / VT_L) for spontaneous breathing trials and 6 mL/kg lung-protective VT.

Choose inputs for the case you are checking

The defaults are illustrative. Replace them with values for your case and keep the units shown beside each field.

  • Spontaneous Respiratory Rate: Spontaneous breathing frequency (breaths/min).
  • Spontaneous Tidal Volume Ml: Spontaneous exhaled tidal volume in mL.
  • Predicted Body Weight Kg: ARDSNet Predicted Body Weight (PBW) in kg for 6–8 mL/kg target.

What the calculation includes

With the default values shown, Rapid Shallow Breathing Index (RSBI) is 57.89 breaths/min/L. The calculation follows RSBI & Ideal Tidal Volume Formula; the formula and variable definitions above show how the inputs combine.

One-input check: With the other defaults held constant, changing Spontaneous Respiratory Rate from 22 breaths/min to 24.2 breaths/min changes Rapid Shallow Breathing Index (RSBI) from 57.89 breaths/min/L to 63.68 breaths/min/L. This is a comparison inside the calculator's stated model, not a prediction.

Where to use caution

  • Uses peer-reviewed clinical and sports physiology formulas.
  • For educational and informational reference only; clinical scores do not replace physician judgment or laboratory reference ranges.

Scope: Global Clinical & Sports Science Consensus Check the assumptions and limitations against your situation before relying on the estimate.

More in Health & Fitness: BMI Calculator (Body Mass Index), Calorie Needs & TDEE Calculator, Running Pace, One-Rep Max (1RM), Target Heart Rate & Calories Burned Calculator.