How Efficiency is Measured

A fireplace’s efficiency is the percentage of the fuel’s heat energy that is actually delivered to the room.

• Open Fireplaces (~5% efficient): Are very inefficient. They can pull more heated air out of your house than they radiate back in, sometimes resulting in a net heat loss.
• Inserts & Stoves (50-80%+ efficient): Create a closed combustion system, allowing you to control airflow. This burns the fuel more completely and radiates far more heat into the room before it’s lost up the chimney.

Important Disclaimer: This calculator uses a simplified heating model based on a typical heating season (approx. 120 days). Actual heating needs, fuel costs, and resulting savings will vary significantly based on your geographical location within the U.S. (e.g., the Northeast vs. the South), local utility rates, and your home’s insulation. This tool is intended for budget planning and educational purposes. Always check with your local fuel suppliers for current pricing.