Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Engineering
HVAC Duct Sizing Calculator
Calculate the required diameter or dimensions of HVAC ducts based on air flow rate and design velocity. Use this when designing ventilation systems to balance air delivery with noise and pressure loss constraints.
Fill in the required fields to see your result.
Engineering
HVAC Heat Load Calculator
Estimates the heating or cooling load for a room or building in BTU/hr based on floor area, ceiling height, insulation quality, temperature difference, and window area. Use it to size furnaces, air conditioners, and heat pumps.
Fill in the required fields to see your result.
Key differences
| HVAC Duct Sizing Calculator | HVAC Heat Load Calculator | |
|---|---|---|
| Category | Engineering | Engineering |
| Inputs required | 4 | 5 |
| Result | Duct Dimension (inches) | Total Heat Load (BTU/hr) |
| What it does | Calculate the required diameter or dimensions of HVAC ducts based on air flow rate and design velocity. Use this when designing ventilation systems to balance air delivery with noise and pressure loss constraints. | Estimates the heating or cooling load for a room or building in BTU/hr based on floor area, ceiling height, insulation quality, temperature difference, and window area. Use it to size furnaces, air conditioners, and heat pumps. |