Single Phase Load Calculator

Calculator Input Form

Load Name

Calculation Mode

Supply Voltage (V)

Input Current (A)

Power Factor

Efficiency (%)

Quantity

Demand Factor

Load Factor

Safety Margin (%)

Hours Per Day

Days Per Month

Electricity Rate Per kWh

Example Data Table

This example shows a common workshop load scenario using the current mode. Values are rounded for readability.

Item	Example Value
Calculation Mode	From current
Supply Voltage	230 V
Input Current	12 A
Power Factor	0.90
Efficiency	95%
Demand Factor	0.85
Load Factor	0.70
Safety Margin	20%
Hours Per Day	8
Days Per Month	30
Rate Per kWh	0.15
Approximate Design Current	12.88 A
Approximate Monthly Energy	373.39 kWh
Approximate Monthly Cost	56.01

Formula Used

Apparent Power: S = V × I

Active Power: P = V × I × PF

Current From Power: I = P / (V × PF)

Current From Apparent Power: I = S / V

Connected Load: Connected Load = Base Load × Quantity

Demand Load: Demand Load = Connected Load × Demand Factor

Input Power: Input Power = Demand Active Power / Efficiency

Design Load: Design Load = Input Power × (1 + Safety Margin)

Average Operating Power: Average Power = Input Power × Load Factor

Daily Energy: Daily kWh = (Average Power / 1000) × Hours Per Day

Monthly Energy: Monthly kWh = Daily kWh × Days Per Month

Monthly Cost: Monthly Cost = Monthly kWh × Rate Per kWh

This calculator assumes a single phase supply and applies the same power factor through the adjusted demand and design stages. Use project standards and local codes for final equipment selection.

How to Use This Calculator

Enter a load name so the report is easier to identify.
Choose whether the known input is current, active power, or apparent power.
Add supply voltage and power factor for the circuit.
Enter efficiency if the load includes a device with conversion losses.
Add quantity, demand factor, and load factor for practical operation.
Set a safety margin to build a design value above the running load.
Enter operating hours, monthly days, and electricity rate.
Click Calculate Load to show results above the form. Then export the report as CSV or PDF.

FAQs

1. What does a single phase load calculator estimate?

It estimates current, active power, apparent power, design load, energy use, and running cost for a single phase electrical load using common planning inputs.

2. Why is power factor important here?

Power factor links active power and apparent power. A lower power factor increases current for the same useful power, affecting circuit sizing and losses.

3. What is the purpose of the demand factor?

Demand factor reduces connected load to a more realistic simultaneous load. It helps planners avoid sizing a circuit only from total nameplate values.

4. Why does the calculator include efficiency?

Efficiency accounts for input losses. If a device is less than fully efficient, the source must deliver more power than the useful output demand.

5. What does load factor change in the report?

Load factor adjusts average operating power for energy and cost estimates. It does not replace demand factor, which is used earlier for diversified loading.

6. Is the breaker size recommendation final?

No. It is a planning recommendation based on calculated design current. Final breaker selection must follow code rules, conductor rating, ambient conditions, and starting current behavior.

7. Can I use this for motors or appliances?

Yes, for preliminary estimates. For motors, also consider inrush current, service factor, duty cycle, and local protection requirements before finalizing equipment.

8. Does this replace a full electrical design review?

No. It supports early sizing and budgeting. Final design should still be checked against standards, manufacturer data, and project-specific installation conditions.