NEC 220 Generator Sizing Report
Prepared by Premier Generators
premiergenerators.com | (615) 645-1DOC

Generator Sizing Calculator

Enter the home's electrical loads below to get a recommended generator size for your project. Calculations follow NEC 220.82 (Optional Method).

Prepared by required

Your contact info, so a Premier specialist can follow up about this sizing.

First name *

Last name *

Email *

Phone *

Company *

Project

Project name

Date

Project address

City

State

ZIP

Electrical service

Service voltage

Build status

Service size (amps)

Fuel type

Natural gas (NG)

Propane (LP)

Diesel

Bi-fuel

Gas meter size (if known)

Supply pressure available

Structure & coverage

Total conditioned sq ft

Sq ft covered by generator

Structure type

Standby scope

Typical loads for this structure type
Central A/C + gas furnace (2-5 ton), electric range or cooktop, electric water heater (~4.5 kW), electric clothes dryer (~5.5 kW), dishwasher, microwave, refrigerator. Add a well pump or pool pump only if present at this site. Verify nameplate values before accepting tool defaults.

HVAC units 0 units

Include all heat pumps, A/C condensers, air handlers, and furnaces. Enter nameplate amperage from the equipment label.

Cooking appliances 0 items

Water heaters 0 units

EV chargers 0 chargers

Per NEC 220.57, list each EVSE circuit. Include level 2 (240V) and DC fast chargers.

Pumps & motors 0 loads

Include well pumps, sewage ejectors, pool/spa pumps, irrigation, and sump pumps. Largest single motor will be calculated at 125% per NEC 430.

Other electrical loads

Clothes washers and refrigerators are already covered by the laundry and small-appliance branch circuits above (NEC 220.52), so they are not entered separately.

Clothes dryer type

Dryer nameplate (watts)

Additional notes / special loads

Transfer switch & installation

Transfer switch type

Transfer switch amperage

Generator location

Sizing method

NEC cycle (override)

Defaults to state cycle (FL 2023, GA 2020, TN 2017). Override only if you know the specific AHJ enforces a different cycle. Always verify with local AHJ before install.

12-month peak demand from utility bills, in kW (optional)

Many homeowners can pull this from their utility app in under a minute. Tool runs the larger of (220.82, Part III, BillingHistory × 1.25); never sizes downward off this number.

Omit CO clearance appendix from printed report

By default the printed PDF includes an appendix with generator placement clearance requirements (NFPA 72, ICC IRC R315). Check this only when the placement walkthrough has already been completed with the customer and the install team.

Attachments 0 files

Helpful to include: a clear photo of your main panel label, site plan or survey, property photos, or any documents you’d like on record. Images will be embedded in the printed report. PDFs will be listed as references (send separately).

Notes

Optional. Site-specific requests, constraints, or questions (runs, landscaping, easements, HOA, preferred install window, etc.).

Results are estimates only; a licensed electrician must verify final sizing and AHJ compliance before installation. Submitting shares this sizing with Premier Generators so we can review it with you and make sure it fits the project.

NEC 220 Load Schedule & Generator Recommendation

Generates a clean PDF report of this sizing for your records or to share with your customer.

Please wait, we are loading the scheduler

Generator Sizing Calculator

NEC 220 Load Schedule & Generator Recommendation