How to use the fan power calculator
Find the air power and shaft power needed by a fan moving a flow against a pressure rise. Enter airflow, pressure rise, fan efficiency in the fields above; the air power, shaft power are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “fan power”, “ventilation fan electricity”, “airflow pressure power”, “calculate fan power”, “find air power”.
Formula
Variables
- Q — Airflow (m³/s)
- dp — Pressure rise (Pa)
- eff — Fan efficiency (%)
Worked example
With airflow = 2 m³/s, pressure rise = 500 Pa, fan efficiency = 65 %, the calculator gives air power ≈ 1 kW; shaft power ≈ 1.538462 kW.
Frequently asked questions
What is the fan power calculator used for?
Find the air power and shaft power needed by a fan moving a flow against a pressure rise. It helps with questions such as “fan power”, “ventilation fan electricity”, “airflow pressure power”.
What is the formula for the fan power calculation?
Air power (kW) = Q × dp / 1000. Shaft power (kW) = [Air power] / (eff / 100). Here Q is airflow (m³/s), dp is pressure rise (Pa), eff is fan efficiency (%).
What inputs do I need for the fan power calculator?
You need airflow in m³/s, pressure rise in Pa, fan efficiency in %. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the fan power calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the fan power result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.