Track Lighting Load Calculator
Calculate the track-lighting line of a commercial NEC Article 220 service or feeder. Enter the track length per run and the number of runs; the tool applies the 220.43(B) 150 VA per 2 feet (or fraction thereof) allowance, reports the 100% calculated load, the 125% continuous figure, and the amperes.
How to use this calculator
- Enter the track length per run in feet. NEC 220.43(B) adds 150 VA for every 2 ft of lighting track, or any fraction of 2 ft.
- Enter the number of identical runs. The "or fraction thereof" round-up is applied to each continuous run separately, so two 3 ft runs carry more load than one 6 ft run.
- For runs of different lengths, calculate each length on its own and add the volt-amperes.
- Pick the voltage and phase of the feeder or panel for the demand-current readout.
- Read the calculated load in volt-amperes and its amperes. The tool shows the number of 2 ft units, the total at 100%, and the 125% continuous figure used for conductor and service sizing.
NEC reference
This calculator follows the National Electrical Code (NEC) 2020. Section 220.43(B) requires an additional load of 150 volt-amperes for every 2 feet of lighting track, or fraction thereof, in occupancies other than dwelling units and the guest rooms or guest suites of hotels and motels. Track lighting is a specific added load, calculated at 100% and not reduced by the Table 220.42 demand factors, and it is typically a continuous load, so conductors and overcurrent devices are sized at 125% of it. The 2023 NEC renumbers this provision to 220.46(B); the 150 VA per 2 feet value is unchanged.
Results are for reference only. Verify against the applicable adopted edition of the NEC and consult a licensed electrician for code compliance.
The track lighting load value (NEC 2020)
The allowance is a fixed volt-ampere figure tied to the length of installed track, not to the number or wattage of the fixture heads mounted on it. A 4-foot track loaded with six small heads and a 4-foot track with two large heads carry the same calculated load.
| Load | NEC section | Allowance |
|---|---|---|
| Track lighting (feeder/service, NEC 2020) | 220.43(B) | 150 VA / 2 ft |
| Track lighting (feeder/service, NEC 2023) | 220.46(B) | 150 VA / 2 ft |
Values are NEC 2020. The 150 VA per 2 feet figure is long-standing; only the section numbering has moved (220.43(B) in 2017 and 2020, 220.46(B) in 2023).
Worked example: a retail store
A retail store has 150 feet of lighting track in one continuous run. Divide the length by 2 feet: 150 / 2 = 75 units. Multiply by 150 VA: 75 × 150 = 11,250 VA of calculated track load at 100%. Because the track lighting operates more than three hours it is a continuous load, so the service-entrance conductors and overcurrent device are sized at 125%: 11,250 × 1.25 = 14,062.5 VA (the tool reports this rounded to a whole 14,063 VA). This method and result match the widely published EC&M and Electrical Contractor Magazine track lighting example.
Why the round-up is per run
NEC 220.43(B) counts 150 VA for every 2 feet of track "or fraction thereof." A run that is not an exact multiple of 2 feet is rounded up to the next whole unit, and that round-up belongs to each physically separate run of track, not to the summed total. Two separate 3-foot runs are each rounded to 2 units, so together they are 4 units (600 VA), while one continuous 6-foot run is 3 units (450 VA). When the runs in a project are different lengths, calculate each length on its own and add the volt-amperes.
Why no demand factor applies
The Table 220.42 demand factors reduce the general lighting load of certain occupancies on the diversity assumption that not every light runs at once. Track lighting is a specific load that NEC 220.43(B) adds at its full calculated value, separate from and on top of the general lighting load, so no demand factor is taken. It is, however, a continuous load, which is why the 125% continuous multiplier is the relevant adjustment when sizing the conductor and overcurrent device.
What this tool does not do
- The 220.43(B) current-limiting device option. Where the track is supplied through a device that limits the current to the track, the NEC permits calculating the load from that device rating instead of 150 VA per 2 feet. That is a design and AHJ decision requiring a listed limiting device; this tool always uses the never-undersize 150 VA per 2 feet basis.
- Conductor, overcurrent device, and neutral sizing. The tool reports the 125% continuous load but selects no wire or device. Size those with the Wire Size, Service Size, Breaker Size, and Neutral Load calculators (NEC 210.19, 240.4, Table 310.16, 220.61).
- The whole-building service calculation. Track lighting is one line of an Article 220 Part III calculation; add general lighting, receptacle, show-window, and kitchen loads with the Commercial Load Calculator.
- Dwelling units and hotel/motel guest rooms. In those occupancies track lighting is included in the general lighting load, so 220.43(B) does not apply.
Frequently asked questions
Is the load based on the fixtures or the track length?
The track length. NEC 220.43(B) sets the load at 150 VA per 2 feet of installed track regardless of how many heads are mounted or their wattage, so the calculated feeder load does not change when heads are added or moved along an existing run.
Is this the same as the whole commercial service calculation?
No. This computes only the track-lighting line. A full commercial service calculation adds general lighting, receptacles, show-window and sign lighting, kitchen equipment, and more. Use the Commercial Load Calculator for the complete service size.
Related calculators
- Show Window & Sign Lighting Load Calculator: the show-window (200 VA/ft) and sign (1200 VA/circuit) lighting lines per 220.43(A)/220.14(F).
- Commercial Load Calculator: the full NEC 220 Part III non-dwelling service calculation that folds in the lighting loads.
- Commercial Receptacle Load Calculator: the general-use receptacle line per 220.14(I) and Table 220.44.
- Service Size Calculator: minimum service disconnect, conductor, and grounding electrode conductor from a known load.
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