Metric Republic / Mechanical & HVAC engineering / Fan Power Calculator

Fan Power Calculator

Estimate air power and fan input power from airflow, pressure rise and efficiency.

Updated September 2026

How it works

Estimate air power and fan input power from airflow, pressure rise and efficiency.

Formula:
Pair = V̇·Δp; Pinput = Pair/η.

Before you use the result: Verify the selected fan against the manufacturer curve and actual control/part-load conditions.

Practical use

Use verified material data and project geometry. Treat results as planning estimates and compare them with the energy/thermal requirements that apply to the project.

Keep units consistent with the source information.
Use project-specific densities, pack sizes and coverage rates where provided.
Round purchasing quantities to supplier packaging and delivery rules.

How to use this calculator: Fan Power Calculator

Estimate air power and fan input power from airflow, pressure rise and efficiency.

Quick workflow

Enter the project values from the latest drawing, specification or verified site measurement.
Check units, material properties, allowances and any code- or supplier-specific parameters before calculating.
Review the result together with the formula, assumptions and the related checks shown on this page.

Worked example

Example inputs: Airflow [m³/h]: 8 000; Total pressure rise [Pa]: 600; Overall fan efficiency [%]: 65.

Using the sample values built into the calculator, the calculation gives approximately: Air power: 1.333 kW; Fan input power: 2.051 kW.

What the result means

Calculation method: Pair = V̇·Δp; Pinput = Pair/η.

Before using the result: Verify the selected fan against the manufacturer curve and actual control/part-load conditions.

Common questions

What does this calculator do?

Estimate air power and fan input power from airflow, pressure rise and efficiency.

Which inputs should I verify?

Key inputs to verify include: Airflow [m³/h], Total pressure rise [Pa], Overall fan efficiency [%].

Can I use this result for final design or ordering?

Use the result as a transparent planning or checking aid. Final design, code compliance, supplier selection and project-specific decisions still need to be verified where applicable. Verify the selected fan against the manufacturer curve and actual control/part-load conditions.

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