Disclaimer: RacewayIQ is an informational engineering tool only. All calculations must be independently verified by the user. Do not rely on these results as the sole basis for design, procurement, installation, construction, permitting, or code compliance decisions.

Panel Load Calculator

Estimate panel design current, utilization, and spare capacity from connected load, demand factor, system voltage, and panel rating. This calculator provides a panel load planning check; final panel calculations may require separate load categories, nonlinear load review, neutral loading review, and local/AHJ requirements.

Job Information

Project nameLocationPrepared byDateNotes

Main Inputs

Panel calculation modeSimple mode uses aggregate continuous and noncontinuous load values. Use project load schedules to build the manual summary.Electrical system

Select the panel electrical system so current is calculated correctly.Nominal panel voltage (V)Use the nominal panel voltage, such as 120/208 V, 120/240 V, or 277/480 V.Continuous connected load (VA)Enter load expected to run for 3 hours or more before applying the continuous-load factor.Noncontinuous connected load (VA)Enter intermittent or noncontinuous load added at 100% before demand factor.Panel bus / main rating (A)

Use the panelboard, switchboard, or distribution equipment ampere rating being checked.

Advanced Inputs

Use these when the job has project-specific assumptions, manufacturer data, or review conditions.

Aggregate demand factorUse 1.0 for no demand reduction. Enter a lower multiplier only when justified by the project load calculation.Continuous-load factorDefault 1.25 represents 125% continuous-load sizing. Change only when criteria differ.Phase Balance ReviewPanel phase balance is not reviewed by this calculator unless detailed phase loading is implemented.

Result

Review

Connected load

30,000 VA

Continuous-load adjustment

2,500 VA

Design load

32,500 VA

Design current

90.2 A

Panel rating

100 A

Panel utilization

90.2%

Remaining capacity

9.8 A

Remaining capacity

3,527 VA / 3.5 kVA

Demand factor used

1.00

Overall status

Review Required

Reason

Panel load is within the selected panel rating but utilization is above the review threshold.

Practical Next Steps

Treat this as a workable planning result that still needs review.
Resolve warnings that are close to limits, based on manual assumptions, or missing manufacturer data.
Confirm the result against the project specification before procurement, permitting, or installation.

A single aggregate demand factor is a planning input. Final panel load calculations may require separate load categories, nonlinear neutral treatment, project-specific demand factors, and local requirements.

Panel utilization is above the review threshold. Review spare capacity, future loads, and project requirements.

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Calculation Breakdown

Load Summary

Panel calculation mode: Simple load summary
Continuous connected load: 10,000 VA
Noncontinuous connected load: 20,000 VA
Connected load: 30,000 VA
Continuous-load factor: 1.25
Aggregate demand factor: 1.00
Phase balance review: Not reviewed

Design Load Calculation

Continuous load contribution: 10,000 VA x 1.25 = 12,500 VA
Continuous-load adjustment: 2,500 VA
Noncontinuous load contribution: 20,000 VA
Design load before demand factor: 32,500 VA
Design load after demand factor: 32,500 VA x 1.00 = 32,500 VA

Panel Current Calculation

Electrical system: Three-phase
Nominal panel voltage: 208 V
Design current: 32,500 VA / (sqrt(3) x 208 V) = 90.2 A

Panel Rating Check

Panel rating: 100 A
Panel utilization: 90.2%
Remaining capacity: 9.8 A
Remaining capacity: 3,527 VA (3.5 kVA)
Result: Review Required
Reason: Panel load is within the selected panel rating but utilization is above the review threshold.

Code and Design References

Panel Load Planning

Panel loading should be reviewed using project load calculations, connected loads, demand factors, continuous-load treatment, and applicable project requirements.

This calculator is a simplified planning check and does not replace a complete panel schedule or load calculation.

Demand Factors

Demand factors may need to be applied by load category rather than as a single aggregate multiplier.

Continuous Loads

Continuous loads may require additional sizing factors depending on the adopted code, equipment, and project criteria.

Neutral and Nonlinear Loads

Nonlinear loads and neutral loading may require separate review.

Spare Capacity

Spare capacity is a design/planning criterion. Confirm owner, project, and future-load requirements.