CO₂ Breathing Emission Calculator
Human respiration releases measurable CO₂. Model the emissions from households, offices, or events by considering activity patterns and group size.
Include sleeping and sedentary time.
E.g., brisk walking, housework.
E.g., running, high-intensity sports.
Per-person emissions
1.63 kg CO₂/day
Group daily emissions
8.13 kg CO₂
Annual emissions
2,966.36 kg CO₂
Equivalent car travel
7,342.46 miles/year
How to Use This Calculator
Count the people
Enter the number of occupants or attendees you want to model.
Break down daily activity
Estimate hours of rest, moderate activity, and vigorous activity for the average person.
Review emissions totals
Use the daily and annual CO₂ outputs to inform ventilation planning or event carbon accounting.
Formula
CO₂ = Σ(Activity Minutes × Resting Factor × Activity Multiplier)
Annual CO₂ = Daily CO₂ × 365
Miles Equivalent = Annual CO₂ ÷ 0.404
Example: A five-person household with 16 resting hours, 60 moderate minutes, and 30 vigorous minutes per person emits ~5.1 kg CO₂/day—equal to driving about 12.5 miles.
Adjust multipliers for athletes or sedentary populations as needed.
About the CO₂ Breathing Emission Calculator
While human respiration is part of the natural carbon cycle, understanding its scale helps contextualize indoor air quality management, event planning, and micro-level carbon accounting.
When to Use This Calculator
- Building design: Estimate occupant-generated CO₂ for ventilation sizing.
- Event sustainability: Include attendee respiration in footprint calculations.
- Education: Illustrate how human activity contributes to CO₂ fluxes.
- Low-carbon planning: Compare human emissions with energy systems in closed environments.
Why Use Our Calculator?
- ✅ Activity aware: Differentiates rest, moderate, and vigorous exertion.
- ✅ Group-friendly: Quickly scales emissions for teams, offices, or events.
- ✅ Clear outputs: Converts CO₂ into relatable car-travel equivalents.
- ✅ Adjustable: Update factors for specific populations or climates.
Common Applications
Hospitals: Evaluate ventilation loads in wards or isolation rooms.
Transit agencies: Assess CO₂ buildup in enclosed trains or buses.
Research labs: Estimate metabolic CO₂ in controlled environment experiments.
Tips for Best Results
- Use wearable or fitness tracker data to refine activity minutes.
- Adjust multipliers for children, elderly, or athletes to reflect metabolic differences.
- Combine with appliance emissions for holistic indoor CO₂ accounting.
- Consider seasonal changes—winter indoor activity often increases emissions per person.
Frequently Asked Questions
Does this include biogenic carbon neutrality?
Yes. Human respiration recycles carbon from food; large-scale mitigation focuses on fossil sources. We model emissions for situational awareness, not carbon crediting.
How accurate are the activity multipliers?
They are based on metabolic equivalent (MET) studies. Adjust to match specific population data if available.
What if my day totals more than 24 hours?
The calculator caps total minutes at 24 hours. Ensure your rest and activity inputs sum to 24 hours or less.
Can I model CO₂ build-up in a room?
Combine the daily per-person emissions with room volume and ventilation rate to estimate concentration changes.