Calculate connected lighting watts, AC apparent load, circuit current, energy, and entered-capacity margin for DC, single-phase, or balanced three-phase circuits.
Trades & Professional Tools · Electrical
Enter your project measurements
Measured inputs · visitor-entered product and design assumptions
1EnterProvide the known values
2CalculateResults update automatically
3VerifyReview the details and units
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Measure using one consistent system. Product coverage, density, resistance, waste, and safety assumptions must come from the actual product data or project specification. Values stay in this browser.
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Calculate connected lighting watts, AC apparent load, circuit current, energy, and entered-capacity margin for DC, single-phase, or balanced three-phase circuits.
At a glance
See the relationship
Circuit voltage (line-to-line for three-phase) (V)Luminaire quantityInput power per luminaire (W)Luminaire power factor (0 to 1)
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Lighting Circuit Load resultThe calculator connects the entered electrical values above to the outputs below. Change one input at a time to see which assumption has the greatest effect.
The relationship
The formula used here
Connected W=quantity×watts. For AC, VA=W/PF and current=VA/(V×phase factor); for DC, PF=1 and current=W/V.
This relationship is applied to the values you enter. Read all relevant outputs together instead of treating one displayed value as a complete electrical decision.
Field reading
Use the result as a next check
Enter a coherent scenario
Keep phase, voltage basis, units, and operating condition consistent across the entered values.
Read the full result
Use manufacturer data and realistic operating assumptions, then treat the result as a planning comparison before ordering equipment or work.
Keep the boundary clear
It does not select luminaires, EV equipment, protective devices, conductors, or an installation method.
Quick guide
How to use this calculator
Choose the calculation mode or measurement system that matches the values you actually have.
Enter measured project dimensions and use product-specific coverage, density, yield, resistance, or waste data where requested.
Review the intermediate results before ordering material or applying the result on site.
Calculation method
Calculation method
Connected W=quantity×watts. For AC, VA=W/PF and current=VA/(V×phase factor); for DC, PF=1 and current=W/V.
The calculator preserves full internal precision and rounds only displayed results. Quantity outputs round up when whole purchasable pieces are required.
Worked example
Worked example
Twenty 20 W luminaires at 0.9 PF on 230 V draw about 1.932 A single phase.
Connected W=quantity×watts. For AC, VA=W/PF and current=VA/(V×phase factor); for DC, PF=1 and current=W/V.
Supported inputs
Precision and limits
Electrical planning boundary
Electrical results use the measured, nameplate, manufacturer, code-table, test, and correction values you enter. They do not select conductors or protective devices, establish breaking capacity or disconnection time, perform coordination or arc-flash studies, approve energized work, or replace the locally adopted code and a qualified electrical professional.
Planning scope
This calculator supports measurement, estimating, and scenario planning. It does not inspect a site, select a product, certify a design, or replace drawings, specifications, manufacturer instructions, local codes, permits, or a qualified trade professional.
Measured and product-specific inputs
Nominal dimensions can differ from actual dimensions. Verify inside pipe diameters, actual lumber sizes, product coverage, bag yield, material density, conductor resistance, waste, and packaging against the materials used on the project.
Safety and regulatory limits
Electrical, HVAC, structural, excavation, roofing, pressure, lifting, and life-safety work may require jurisdiction-specific calculations and professional approval. Do not use a generic planning result as a code-compliance or safety determination.
Precision and privacy
Inputs accept bounded plain decimals. Calculations remain in this browser and raw entered project values are not submitted to 365CALCS.COM.
