Residential Electrical Load Calc Skip to main content
Electrical Free Pro Features Available

Residential Electrical Load Calculator (NEC 220)

Calculate service size and feeder demand using NEC 220.82 and 220.83 with step-by-step demand factor breakdowns

residential load screen for early electrical review. Enter dwelling area, appliance prompts, HVAC prompts, EVSE prompts, and existing-service prompts to see local demand arithmetic, cached service-size rows, cached conductor-row prompts, and source warnings. The app preserves legacy 220.82/220.83-style math but does not reproduce the current NEC, determine optional-method eligibility, approve a service size, choose conductors or breakers, prepare a permit submittal, satisfy the utility, or replace AHJ and qualified electrical review.

Pro Tip: Treat every favorable or unfavorable result as a question list for the electrician, engineer, utility, and AHJ. Confirm the adopted NEC edition, local amendments, 2026 renumbering or reorganization, exact nameplates, MCA/MOCP, EVSE settings, energy management, service equipment, conductor method, terminal ratings, available fault current, grounding/bonding, permit requirements, and inspection basis before buying equipment or changing a service.

Check individual panel loading and circuit distribution

Panel Load Study →

Review panel-fit prompts for an EV charger addition

EV Charger Load & Panel Fit Check →

Review conductor ampacity and voltage-drop prompts

Wire Sizing Calculator →

Check standby-generator load prompts for source review

Generator Sizing Calculator →

PREVIEW All Pro features are currently free for a limited time. No license key required.

Residential Electrical Load Calculator (NEC 220)
Pop Out

How It Works

  1. Choose the Local Prompt Method

    Choose the legacy 220.82-style new-dwelling prompt or the legacy 220.83-style existing-dwelling prompt. Verify adopted edition, local amendments, eligibility, and AHJ interpretation outside the app.

  2. Enter Dwelling and Existing-Service Prompts

    Enter area or existing-service values only when those values already come from project records, measurements, utility data, or qualified review.

  3. Enter Equipment Prompts

    Use actual appliance, EVSE, HVAC, MCA/MOCP, and nameplate information. Manual J, Manual S, EVSE load management, product listing, and manufacturer instructions remain external checks.

  4. Review Cached Rows

    Review total VA, amp prompt, cached service-size row, utilization prompt, and cached conductor rows as source-gap prompts rather than approval to install.

  5. Carry Gaps Forward

    Use adopted NEC, utility requirements, service equipment listings, conductor/OCPD design, grounding and bonding review, permits, inspections, NFPA 70E/OSHA safe-work controls, and AHJ review before field use.

Built For

  • Electricians collecting early load prompts before preparing a calculation of record
  • Engineers comparing local assumptions before adopted-code and utility review
  • Inspectors identifying missing nameplate, service-equipment, conductor, or AHJ records
  • Homeowners preparing questions before adding EVSE, heat pumps, or major electric appliances
  • Contractors budgeting electrical-service scope without treating the calculator as approval

Assumptions

  • Local legacy 220.82/220.83-style arithmetic is preserved as a deterministic prompt only.
  • Single-phase 120/240 V dwelling-service prompt is assumed for amp conversion.
  • EVSE preset rows use a local 125 percent continuous-load prompt only.
  • Cached conductor rows are not licensed NEC table reproductions or product-listing checks.

Limitations

  • Does not determine adopted NEC edition, local amendments, optional-method eligibility, 2026 renumbering, utility requirements, permit readiness, or AHJ acceptance.
  • Does not select service equipment, breakers, conductors, wiring methods, grounding/bonding, neutral sizing, or available-fault-current labels.
  • Does not perform Manual J, Manual S, EVSE load-management approval, voltage drop, arc-flash, shock, LOTO, or safe-work planning.

References

  • NFPA 70 2026 National Electrical Code source pointer.
  • NFPA 70E and OSHA 1910.303 source pointers for electrical safe-work and installation context.
  • UL 854, DOE AFDC EV charging, ACCA Manual J/S, and NIST source pointers for service-conductor, EVSE, HVAC, and unit context.

Frequently Asked Questions

They are local labels for two legacy dwelling-load prompt paths. The adopted NEC edition, 2026 reorganization or renumbering, local amendments, eligibility, utility rules, and AHJ direction determine the actual calculation path.
No. It displays cached service-size prompts from local arithmetic. Final service size depends on adopted code, utility service, service equipment, load inventory, conductors, OCPD, available fault current, permits, inspections, and qualified review.
Use project-specific Manual J/Manual S/OEM/nameplate values. The app only compares the entered electric heating prompt and cooling prompt; it does not determine design loads, equipment capacity, auxiliary heat behavior, or commissioning requirements.
No. A high or low local prompt only identifies a review need. Service upgrades, load management, panel changes, meter/main work, utility coordination, and AHJ acceptance require qualified electrical review.
No. Conductor and OCPD decisions require the adopted NEC, terminal ratings, conductor material and insulation, wiring method, ambient and bundling conditions, voltage drop, utility requirements, product listings, and AHJ review.
The app applies only a local continuous-load prompt to the entered EVSE row. Real EVSE design must verify Article 625 requirements, load management if used, product instructions, utility rules, permits, and AHJ review.
Disclaimer: This tool provides preliminary source-aware residential load prompts only. It is not an NEC calculation of record, permit drawing, utility service request, service upgrade approval, conductor or breaker selection, inspection result, AHJ approval, or safe-work authorization.

Learn More

Electrical

Residential Load Source Boundaries

Source-boundary guide for local residential service-load prompts, legacy 220.82/220.83 labels, adopted NEC review, equipment data, EVSE, utility, conductors, permits, and AHJ gaps.

Read Guide →

Related Tools

Electrical Live

Can I Run This On That?

Check if your circuit breaker and wiring can handle a specific appliance. Enter breaker size, wire gauge, and load wattage for a pass/fail verdict based on NEC standards.

Launch Tool →
Electrical Live

Wire Sizing Calculator

Find the right AWG wire gauge for any electrical run. Enter amps, distance, and voltage to get NEC-compliant sizing with derating, voltage drop, and copper vs aluminum cost comparison.

Launch Tool →
Electrical Live

Generator Sizing Calculator

What size generator do you need? Add your appliances and loads to calculate total running watts and starting surge. Get a recommended generator size with built-in headroom.

Launch Tool →