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Load Calculation Documentation: Making Your Calc Submittal-Ready

A correct final number is not enough. The reviewer needs to see the method, the inputs, where those inputs came from, and how the calculation reached the result. If a stranger cannot follow it without calling you, the package is not finished.

The arithmetic and the documentation are separate jobs. This page is about finishing the second one.

What “submittal-ready” actually means

Your calc is ready when it answers four questions on its face:

1. What method? Which calculation approach you used, and under which code edition. The NEC provides more than one recognized method for dwelling and service calculations; the reviewer needs to know which one they’re checking, cited to the edition your jurisdiction enforces — editions renumber and revise, so “the code says” without an edition is not a citation.
2. What inputs? Every load you counted, with its source: the square footage and where it came from, the fixed appliances from the plans or the site, the HVAC nameplate values, the largest-motor identification. An input without a source is an assumption wearing a costume.
3. What factors? Where you applied demand factors or diversity, say so explicitly — the reviewer should never have to reverse-engineer why a number shrank.
4. What result, applied how? The computed load, the service or feeder size selected, and the margin between them.

The provenance rule

Use the same discipline found in a good engineering submittal: every number in the calc carries one of three tags — measured (you read it off a nameplate or a drawing; say which), specified (the plans or the customer fixed it; cite the sheet), or assumed (you chose it, and you say why). This does not guarantee an approval. It gives the reviewer a traceable package and gives you a clean place to correct an input when something changes.

Compute with a stated method — not a habit

However you run the arithmetic — by hand, spreadsheet, or software — the documentation requirement is identical: the method must be named and the intermediate values must be visible. A bare final number is unverifiable by construction.

Where a calculation is your next action, the free calculators at circuitcalcs.com compute service/feeder sizing, conduit fill, and voltage drop with the method stated and the intermediate values shown — each result carries the same edition and jurisdiction caveats this page does.

The submittal package

What goes in the envelope (or the portal upload), in order: the calc summary sheet (one page: method + edition, total computed load, service size selected) · the input inventory with provenance tags · the calculation detail with intermediate values · supporting documents you relied on (nameplate photos, plan sheets cited) · your license and contact block. One page of summary, then the evidence. Reviewers can only verify what they can follow.

The three rejections you can prevent today

1. No edition stated. The reviewer can’t check a calc against an unnamed rulebook.
2. Untraceable inputs. A square footage that matches no drawing or an appliance load with no identified source forces the reviewer to stop and ask where the number came from.
3. Invisible demand factors. A total that’s smaller than the sum of its parts, with no explanation, reads as an error even when it’s correct.

Whether your jurisdiction requires a load calc for your specific job, and in what form, is the AHJ’s call — this page makes no claim about any jurisdiction’s submittal requirements.

Get the calc documentation template

The working template includes the summary, method record, provenance-tagged input inventory, calculation-detail table, supporting-document list, assumption log, revision record, and final submittal check.

Provided by ElectricalDocs. No calculation value on this page is hand-typed; worked examples live in the calculators themselves, computed by the calculation engine.