Electrical Load Calculator
Estimate total electrical demand, apparent power and current from connected load, demand factor, voltage, phase factor and power factor. Enter project-specific values and review every assumption before using the estimate.
Fill in the required fields to see your result.
Use this calculator on your website
Add this free Electrical Load Calculator to your blog, article, or business website. Copy the embed code and publish it in minutes.
Perfect for blogs, WordPress, Webflow, and business websites.
The primary result shows the main estimated capacity, current, airflow, metric or business value. Supporting outputs expose intermediate calculations.
Need a calculator like this?
Calciro can build a custom calculator around your formulas, pricing rules, or lead-generation process.
How to Use This Calculator
Enter the requested values using the units shown. Confirm that all inputs describe the same period, system or project.
Formula & Methodology
The calculator applies the displayed arithmetic or engineering formula directly to the entered values without silently adding hidden assumptions.
Worked example
Use a phase factor of 1 for basic single-phase calculations or approximately 1.732 for balanced three-phase line-to-line calculations.
Results may omit equipment-specific starting current, conductor temperature, derating, local codes, climate design data, duct losses, static pressure, infiltration and building-envelope details.
Educational preliminary estimate only. Not an electrical design, HVAC load calculation, permit document or code-compliance determination. Work on electrical and mechanical systems should be verified by qualified professionals.
Related Calculators
Related Guides
- How to Convert Amps to Kilowatts: Single-Phase and Three-Phase FormulasConvert amps to kilowatts using the correct formula for single-phase or three-phase circuits. Covers power factor, worked examples, and a quick reference table.
- How Three-Phase Power Is Calculated: Watts, Amps, and Power FactorUnderstand three-phase power calculations — how to find real power (kW), apparent power (kVA), reactive power (kVAR), and current from three-phase motor and generator specifications.
- Electrical Load Calculator: How to Estimate Home Panel and Circuit LoadsLearn to calculate your home's electrical load for panel sizing, service entry, and circuit planning. Covers NEC Standard Method, demand factors, and what drives panel capacity.
- Generator Sizing Guide: How Many Watts Do You Actually Need?Calculate generator wattage for home backup or job site use. Covers running vs. starting watts, essential circuit loads, and the difference between portable and whole-home standby generators.
- Wire Size Calculator: How to Choose the Right AWG for Any CircuitLearn how to select the correct wire gauge (AWG) based on ampacity, run length, and NEC requirements. Includes the standard wire-to-breaker pairing table and when to upsize.
Frequently Asked Questions
- What does the Electrical Load Calculator calculate?
- Estimate total electrical demand, apparent power and current from connected load, demand factor, voltage, phase factor and power factor.
- Are the results guaranteed or code-compliant?
- No. It is a preliminary educational estimate and does not establish code compliance, equipment suitability, permit approval or installation safety.
- Can I change the assumptions?
- Yes. The calculator exposes the main design, operating or financial assumptions so you can replace examples with project-specific values.
- Should the result be independently verified?
- Yes. Verify the result with applicable codes, manufacturer data, approved load calculations and a qualified electrician, engineer or HVAC professional.
Last updated 7/21/2026