Convert an entered breathing scenario into CO₂ gas volume and mass for a selected duration.
Inputs and method
CO₂ volume = breaths/min × litres/breath × CO₂ fraction × minutes. Mass = volume × the entered gas density.
All empirical factors, rates, percentages, clearances, product yields, and model values shown as inputs are scenario values supplied by you. Their source or measurement basis appears beside the inputs and result. Units remain visible, calculations use unrounded values, and rounding occurs only for display or a whole-package ceiling.
Interpreting the result
Breathing values and the temperature/pressure density basis are user assumptions. The result is not a personal footprint or medical estimate.
Treat scenario ranges as sensitivity ranges, not confidence intervals. Check the factor’s version, geography, population or product, system boundary, and date before using the result. A finite arithmetic result does not establish code compliance, certification, safety, forecast accuracy, or model validity.
Validation and rounding
The calculator rejects blank required factors, invalid numeric, prohibited negatives, impossible relationships, and unsupported modes. No malformed value silently selects another branch. Continuous outputs use the precision displayed in the result; package quantities round up only after waste is applied.
Worked example
At 12 breaths/min, 0.5 L/breath, 4% CO₂, and 60 min, volume is 14.40 L. At 1.842 g/L, mass is 26.52 g CO₂.
Frequently asked question
Is this a personal carbon-footprint estimate? No. It is gas-volume and density arithmetic under the entered physiology and temperature/pressure basis. For scenario-style footprint estimates in other areas, see the Meat Footprint Calculator, Flight Emissions Calculator, and Home Energy Efficiency Calculator.
Keep the physiology and gas basis together
Record the source and conditions for tidal volume, exhaled fraction, and gas density before entering the duration. Compare a different duration with those assumptions fixed, then examine a different assumption set as a separate scenario. This keeps a time-scale change distinct from a change in the physiology or density model.
| Assumption group | Record to retain |
|---|---|
| Breathing | Breaths per minute and tidal volume per breath |
| Gas | Exhaled CO₂ fraction and density basis |
| Interval | Duration in minutes |
| Evidence | Physiology source, density conditions, and uncertainty notes |
Sources
- U.S. EPA, “Overview of Greenhouse Gases” — current web edition; Carbon Dioxide section, accessed 2026-07-09. Route-specific boundary: context and terminology only; it does not supply an entered coefficient, uncertainty, recommendation, or approval.
- IPCC, “AR6 Working Group I: The Physical Science Basis” — 2021 report landing page; Summary and report-scope passages, accessed 2026-07-09. Route-specific boundary: context and terminology only; it does not supply an entered coefficient, uncertainty, recommendation, or approval.
- FAO, “Tackling Climate Change Through Livestock” — 2013 report; executive-summary system-boundary passages, accessed 2026-07-09. Route-specific boundary: context and terminology only; it does not supply an entered coefficient, uncertainty, recommendation, or approval.