2023 NEC • 220.82 / 220.84 / 220.85 • 220.61 Neutral
Optional Method Master Calculator
Single dwelling, two-family, and multifamily optional-method calculator with edition-aware switching for 2020, 2023, and 2026 NEC, upgraded cooking engines, corrected voltage-drop targets, separate neutral worksheet, conductor review, and voltage-drop review.
Step 1 — Project, NEC Edition, and Mode
2020/2023 use 220.82, 220.84, and 220.85. 2026 uses 120.82, 120.84, and 120.85, and changes dwelling-unit floor area from 3 VA/ft² to 2 VA/ft².
Step 2A — Single Dwelling Optional Method
Enter the optional-method loads by nameplate or selected helper path. This is not the Part III standard method.
2020/2023 = 3 VA/ft². 2026 = 2 VA/ft².
Cooking Engine
Manual value overrides helpers when greater than 0.
HVAC Engine
Step 3 — Conductor Sizing Engine
Step 4 — Voltage Drop Review
Branch circuit review defaults to 3%.
Step 5 — Neutral Worksheet
Neutral is separate from the optional-method phase-conductor total. This worksheet uses separate neutral logic, including 70% for ranges and dryers.
Step 6 — Results
Total Optional-Method Load 0 VA Selected engine total
Calculated Current 0 A Calculated from selected system
Rounded-Up Standard Size — Helpful reference only
310.12 Preview Review Only where actual scope fits
Step 7 — Summary / Print / Save
This version includes 2020, 2023, and 2026 NEC switching, separate optional-method paths, upgraded cooking engines in all dwelling blocks, corrected voltage-drop design targets, and a separate neutral worksheet with ranges and dryers at 70%.