Commercial Receptacle Load Calculator
Isolate the general-use receptacle line of a commercial (other-than-dwelling) NEC Article 220 calculation. Enter the receptacle count; the tool applies the 220.14(I) 180 VA per strap and the Table 220.44 demand factors, adds the 220.14(K) 1 VA/ft² floor for banks and office buildings, and reports the governing load and its amperes.
How to use this calculator
- Enter the number of general-use receptacle straps (yokes). Each single or multiple receptacle on one strap is 180 VA (NEC 220.14(I)); a duplex receptacle is one strap.
- Choose the occupancy. A bank or office building also applies the 220.14(K) 1 VA/ft² floor; enter the building floor area when that field appears. If the receptacle count is unknown, enter 0 and the floor area.
- Pick the voltage and phase of the feeder or panel for the demand-current readout.
- Read the governing receptacle load in volt-amperes and its amperes. The tool shows the connected load, the Table 220.44 demand, and (for offices/banks) the 1 VA/ft² alternative, and marks which one governed.
NEC reference
This calculator follows the National Electrical Code (NEC) 2020. Section 220.14(I) sets the general-use receptacle outlet load at 180 volt-amperes per strap; Table 220.44 gives the non-dwelling receptacle demand factors (first 10 kVA at 100%, remainder at 50%); and Section 220.14(K) requires banks and office buildings to use the larger of that demand-factored load or 1 VA per square foot. These provisions are unchanged across the 2017, 2020, and 2023 editions, so no edition toggle is offered.
Results are for reference only. Verify against the applicable adopted edition of the NEC and consult a licensed electrician for code compliance.
NEC 2020 Table 220.44 receptacle demand factors
The demand factors apply to the total general-use receptacle load of a non-dwelling occupancy, computed at 180 VA per strap. The reduction on the portion above 10 kVA reflects the diversity assumption that not every receptacle is loaded at once.
| Portion of receptacle load | Demand factor |
|---|---|
| First 10 kVA (10,000 VA) | 100% |
| Remainder over 10 kVA | 50% |
Factors are NEC 2020 Table 220.44 (receptacle loads, other than dwelling units). Receptacle straps are counted at 180 VA each per 220.14(I).
Worked example: 800 receptacles
A commercial building has 800 general-use receptacle straps. At 180 VA each the connected receptacle load is 800 × 180 = 144,000 VA. Table 220.44 takes the first 10,000 VA at 100% and the remaining 134,000 VA at 50% (67,000 VA), so the receptacle demand is 10,000 + 67,000 = 77,000 VA. On a 480 V, 3-phase feeder that is 77,000 / (480 × 1.732) = 92.6 A. This matches the widely published EC&M and IAEI Article 220 receptacle example.
Banks and office buildings: the 220.14(K) floor
For a bank or office building, NEC 220.14(K) does not let the receptacle load fall below 1 VA per square foot of building area. The receptacle load is the larger of the Table 220.44 demand-factored figure or the 1 VA/ft² value. Consider a 20,000 ft² office with 50 receptacle straps: the connected load is 9,000 VA and, being under 10 kVA, its demand is 9,000 VA, but 20,000 ft² × 1 VA/ft² is 20,000 VA, so the 1 VA/ft² floor governs. With 200 straps in the same office the receptacle demand is 23,000 VA, which exceeds the 20,000 VA floor and governs instead. When the receptacle count is not yet known, the 1 VA/ft² value is used on its own.
What this tool does not do
- Fixed multioutlet assemblies (NEC 220.14(H)). Plugmold-type assemblies are calculated at 180 VA per 5 ft, or per 1 ft where used simultaneously, a separate rule from the per-strap 220.14(I) receptacle load.
- Dwelling-unit receptacles. These are included in the general lighting VA/ft² load (220.14(J)), not counted individually. This tool is for non-dwelling occupancies.
- The rest of the building service. Receptacles are one line of an Article 220 Part III calculation; add general lighting, kitchen, show-window/sign, and other loads with the Commercial Load Calculator.
- Conductor, overcurrent device, and neutral sizing. Size those with the Wire Size, Breaker Size, and Neutral Load calculators (NEC 210.19, 240.4, Table 310.16, 220.61).
Frequently asked questions
Is a duplex receptacle 180 VA or 360 VA?
180 VA. NEC 220.14(I) counts 180 VA for each single or multiple receptacle on one strap. A duplex receptacle is a single strap, so it is 180 VA. A yoke carrying more than one receptacle is still one strap. Only fixed multioutlet assemblies use a different, length-based rule (220.14(H)).
Does the 10 kVA at 100% apply once for the whole building?
Yes. Table 220.44 applies the 100% factor to the first 10 kVA of the total non-dwelling receptacle load and 50% to everything above it, once across the receptacle total, not per circuit or per panel.
Is this the same as the whole-building commercial load calculation?
No. This computes only the general-use receptacle line, with the 220.14(K) office/bank floor made explicit. A full commercial service calculation adds general lighting, kitchen equipment, show-window and sign loads, and more. Use the Commercial Load Calculator for the complete service size.
Related calculators
- Commercial Load Calculator: the full NEC 220 Part III non-dwelling service calculation that folds receptacles into the whole building.
- Commercial Kitchen Equipment Demand Calculator: the Table 220.56 kitchen equipment demand line, with the two-largest-loads floor.
- Service Size Calculator: minimum service disconnect, conductor, and grounding electrode conductor from a known load.
- Wire Size Calculator: the feeder conductor for the receptacle load, for ampacity and voltage drop.
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