Lung Capacity Calculator - Vital Capacity and TLC

A lung capacity calculator is a clinical estimator that uses your age, sex, and height to predict the volumes of air your lungs can hold and move. It applies the prediction equations published by the European Respiratory Society to a healthy reference population, then reports the vital capacity, total lung capacity, inspiratory capacity, and residual volume you would expect for someone of the same build. Use it to set a baseline, to interpret a recent spirometry reading, or to track how training, age, or recovery change your breathing.

• • Estimate your personal vital capacity: Plug in your age, sex, and height to see the maximum liters of air you should be able to expel after a deep breath, and compare to a measured value from a spirometer.
• • Interpret a recent spirometry report: Enter the vital capacity your clinician measured and read the percent-of-predicted row to see whether the reading sits in the 80-120% range or falls outside it.
• • Track changes after illness or training: Re-run the calculator after pulmonary rehab, an aerobic training block, or recovery from pneumonia to compare against an earlier baseline.
• • Set realistic breathing goals for endurance sports: Runners, cyclists, swimmers, and singers often use a predicted TLC and inspiratory capacity to size breath-control drills.

The calculator does not measure anything. It returns a population average validated against tens of thousands of healthy non-smokers in the ERS reference data set, so think of the result as a reference number, not a diagnosis. If you sit outside the 18-90 year range, the prediction equations no longer apply without adjustment.

Because both calculators use the same three demographic inputs, the ideal body weight calculator is a natural companion for anyone who wants a full body-metric snapshot in one sitting.

The lung capacity calculator takes the three inputs you provide, runs them through a sex-specific linear regression, and then derives the four standard lung volumes and capacities from that single primary result. The math is short, the assumptions are documented, and every output traces back to a published reference equation.

• Height (cm): Standing height in centimeters. Each added centimeter adds about 57.6 mL of predicted VC in males and 44.3 mL in females.
• Age (years): Age in whole years. The regression subtracts about 26 mL per year in males and 24 mL per year in females after the early 20s.
• Sex: Selects the correct set of regression coefficients, since males and females have different chest-wall geometry.
• Measured VC (L): Optional input. When supplied, the calculator divides the measured vital capacity by the predicted VC to give a percent-of-predicted value.

After the predicted VC is computed, the calculator derives total lung capacity, residual volume, inspiratory capacity, and the percent-of-predicted reading from a single ratio. The 0.80 factor scales VC up to TLC because vital capacity represents about 80% of total lung capacity in healthy adults.

According to Quanjer et al., 1993 (European Respiratory Journal), predicted vital capacity for adult males is VC (L) = 0.0576 × H (cm) - 0.026 × A (years) - 4.34 and for adult females is VC (L) = 0.0443 × H (cm) - 0.024 × A (years) - 2.85.

A BMI calculator answers the weight-versus-height question with a single number, and the lung capacity calculator answers the same kind of question about the chest cavity rather than the whole body.

Four ideas show up in every lung function report. Understanding them turns the calculator output into a number you can act on.

These four volumes combine in a fixed way. VC = TV + IRV + ERV, and TLC = TV + IRV + ERV + RV, so a change in any one of them propagates to the others.

The residual volume and inspiratory capacity concepts matter most when they are read alongside body composition, so pairing the lung capacity calculator with a body fat percentage calculator gives a fuller picture of the same person.

Five quick steps turn your age, sex, and height into a full lung-volume breakdown.

1. 1 Pick the correct sex: Choose male or female from the first dropdown. The calculator switches its regression coefficients based on this choice, so the wrong selection can change the predicted VC by more than a liter.
2. 2 Enter your age in years: Use your age at the time you want the prediction, rounded to the nearest whole year. The age coefficient reduces predicted VC by about 25 mL per year after the early 20s.
3. 3 Enter your standing height in centimeters: Measure barefoot against a wall. If you only know your height in feet and inches, multiply inches by 2.54 and add the feet × 30.48 conversion.
4. 4 Add a measured vital capacity if you have one: If a clinician or a home spirometer has given you a measured VC, type it in liters. The percent-of-predicted row will then tell you how your reading compares to the population average.
5. 5 Read the result panel and act on it: Start with the predicted VC as your baseline. The TLC, IC, and RV rows show derived capacities you would expect on a full pulmonary function test.

A 35-year-old female at 168 cm with a home spirometer reading of 3.2 L gets a predicted VC of 3.66 L and a percent-of-predicted value of 87%, which sits inside the normal range.

The calculator is most useful when paired with a real measurement, but the predicted numbers alone already help with planning, screening, and motivation.

• • Sets a baseline before training or illness: Run the calculator when you start a swim program, begin pulmonary rehab, or recover from a respiratory infection. The predicted VC gives you a comparison number to revisit in 4-8 weeks.
• • Translates a raw spirometry reading: A measured VC of 4.0 L means very different things for a 5'2" 70-year-old and a 6'2" 25-year-old. The percent-of-predicted row puts both readings on the same scale.
• • Identifies the dominant input quickly: Because the formula is linear, a 5 cm increase in height adds about 0.29 L of VC for males and 0.22 L for females, which is more than the typical 0.13 L drop from a 5-year increase in age.
• • Supports athletic and singing breath goals: Endurance athletes, freedivers, and singers can size their breath-hold and breath-control drills to the predicted TLC and inspiratory capacity rather than guessing.
• • Costs nothing and runs in your browser: The same prediction equations a clinic uses live in the calculator, so you can revisit the model as often as your training or recovery plan needs.

If a measured value is unavailable, the predicted value still works as a training target because the model is calibrated to healthy non-smokers, not to athletes or patients.

Endurance training targets are usually written in calories per day, so a TDEE calculator helps translate the new predicted inspiratory capacity and TLC into the energy budget that actually drives the adaptation.

Four biological and behavioral factors move a predicted vital capacity up or down, and two caveats are worth keeping in mind before you act on the output.

• • The calculator outputs are predictions, not measurements. A 30% gap between the predicted and measured VC may reflect technique or recent illness rather than lung disease.
• • The percent-of-predicted row is only meaningful when a measured VC is supplied. Leaving the field at 0 just reports 100% as a placeholder.

Two related ratios used by clinicians can be derived from these numbers. The RV/TLC ratio of 0.20 reflects a healthy adult pattern, and the FEV1/FVC ratio used in obstructive-disease screening depends on a separate one-second forced expiration the calculator does not estimate.

According to ATS/ERS 2019 Spirometry Standardization Statement, lung volumes and capacities in healthy adults follow standard reference ratios such as a residual volume of about 20% of total lung capacity, a functional residual capacity of about 40% of total lung capacity, and a tidal volume of roughly 0.5 L per breath.

Hydration changes the thickness of the airway lining and therefore the measured vital capacity, so a daily water intake calculator is worth pairing with the lung capacity output on hot training days.