Free Building Science Calculators for Residential Energy Efficiency Professionals
The Weatherization Assistance Program (WAP) and the Building Technologies Office (BTO) of the Department of Energy (DOE) have collaborated to purchase the RED Calc Free and RED Calc Pro web app software tools. The entire suite of tools is now free for all to use.
Tool Categories:
Ventilation Sizing | Airflow Measurement | Insulation | Domestic Hot Water | Moisture | Electrical Use | Weather Data
Stand-alone RED Calc Tools
This is a collection of stand-alone calculation tools. Try these tools for one-off situations for a quick calculation that you do not need to save or print a report - no login required.
RED Calc Pro Web App
This is a full mobile-first web application. A more professional experience of the RED Calc tools. Organize your work in folders. Cloud storage allows you to access your data from multiple devices. Switches to off-line mode when there is no internet connection. Generate PDF reports. Requires log-in with a free account.
[COMING SOON]
Who uses RED Calc Tools?
Wx Assistance (WAP)
- Energy auditors
- Inspectors
- QC inspectors
- Monitors
- Crew leaders
- Subcontractors
- Trainers
Home Performance
- Contractors
- Energy auditors
- Ventilation designers
- Inspectors
- QC inspectors
- Program designers
Utilities
- Energy auditors
- Inspectors
- QC inspectors
- Subcontractors
- Trainers
Code Enforcement, etc.
- CEOs
- Home builders
- Research analysts
- Engineers
- Building science instructors
- Homeowners