Air Motor Energy Calculator

Calculator

Torque

Torque Unit

Speed

Enter revolutions per minute.

Run Time

Time Unit

Duty Cycle (%)

Supply Pressure

Pressure Drop

Pressure Unit

Air Flow Per Motor

Flow Unit

Motor Count

Load Factor (%)

Target Motor Efficiency (%)

Compressor Efficiency (%)

Electricity Rate Per kWh

Formula Used

The calculator first converts every input to SI units.

Angular speed: ω = 2πN / 60
Shaft power: P_shaft = T × ω × load factor × motor count
Active time: t = run time × duty cycle
Output energy: E_out = P_shaft × t
Air input power: P_air = working pressure × total flow
Air input energy: E_air = P_air × t
Computed efficiency: η = E_out / E_air × 100
Cost: compressor kWh × electricity rate

How to Use This Calculator

Enter the motor torque and select its unit.
Enter shaft speed in revolutions per minute.
Add run time and duty cycle.
Enter supply pressure and expected pressure drop.
Enter air flow per motor and choose its unit.
Add motor count, load factor, efficiency, and cost data.
Press Calculate to see the result above the form.
Use CSV or PDF buttons to save the calculation.

Example Data Table

Torque	Speed	Time	Flow	Pressure	Output Energy	Air Energy	Efficiency
12 N·m	1800 rpm	30 min	0.75 m³/min	6 bar	1.131 kWh	3.750 kWh	30.2%
5 N·m	3000 rpm	15 min	0.40 m³/min	5.5 bar	0.393 kWh	0.917 kWh	42.9%
22 N·m	900 rpm	60 min	1.10 m³/min	6.2 bar	2.073 kWh	11.367 kWh	18.2%

Air Motor Energy Basics

An air motor converts compressed air into shaft rotation. It is useful where sparks, heat, or overload risk must stay low. This calculator estimates output energy, input air energy, efficiency, and air cost. It also reports speed in radians per second.

Why Energy Matters

Energy tells you how much useful work the motor can deliver over time. Power shows the work rate. Energy combines power and run time. This helps compare tools, mixers, hoists, pumps, and compact drives. It also helps estimate air demand before a compressor is selected.

Key Inputs

Torque is the turning force at the shaft. Speed is entered in revolutions per minute. Run time is the active operating duration. Air flow is the supplied volume rate. Pressure is the working gauge pressure. Efficiency adjusts the ideal shaft estimate to a realistic output.

Pressure and Flow Notes

Air systems lose pressure through hoses, filters, valves, and fittings. Use pressure measured near the motor when possible. Flow should match the stated basis. This tool treats the entered flow as delivered air flow for a practical energy estimate. If you use free air flow, results may differ from measured line conditions.

Cost Planning

Compressed air is convenient but often costly. Leaks, poor hose sizing, and excessive pressure increase energy use. The cost estimate uses electrical price and compressor efficiency. It is only a planning value. Actual cost depends on compressor type, controls, duty cycle, and maintenance.

Using Results

Compare output energy with input energy. A low efficiency result can mean oversized supply pressure, worn vanes, poor lubrication, or wrong speed. Check the specific energy value too. It shows energy used per unit of useful work. Smaller values are usually better.

Practical Tips

Select a motor with reserve torque. Avoid running at stall for long periods. Keep the air dry and filtered. Follow lubrication requirements. Use short hoses with proper diameter. Record pressure during operation, not while idle. Recheck results after changing nozzles, gears, or loads.

Safe Interpretation

This calculator supports estimation only. It does not replace motor curves from a manufacturer. Always check rated pressure, speed, torque, and duty limits before final design. Use certified data for safety critical machinery, lifting equipment, or regulated installations.

FAQs

What is air motor energy?

Air motor energy is the useful work produced by the rotating shaft over time. It depends on torque, speed, load, motor count, and active operating time.

Why does the calculator use torque and RPM?

Torque and RPM define shaft power. Torque shows turning force. RPM shows rotation speed. Together they estimate mechanical output power.

What pressure should I enter?

Use the pressure measured near the motor during operation. This gives a better result than idle compressor pressure at the tank.

What does pressure drop mean?

Pressure drop is the loss through hoses, valves, filters, fittings, and regulators. The calculator subtracts it from supply pressure.

Can I use free air flow values?

You can enter them for planning, but results may differ. The calculator treats flow as delivered flow in the working line.

Why is my computed efficiency above 100%?

That usually means one input is inconsistent. Check torque, speed, pressure, flow, units, and pressure drop before using the result.

Does this replace a manufacturer data sheet?

No. Use it for estimates and comparisons. Final selection should use certified motor curves and duty ratings from the supplier.

What affects air motor running cost?

Cost depends on air flow, pressure, duty cycle, compressor efficiency, leaks, controls, maintenance, and electricity price.