Commercial Kitchen Equipment Demand Calculator
Apply the NEC Table 220.56 demand factors to commercial kitchen equipment and get the governing feeder or service demand. Enter each unit of equipment; the tool applies the demand factor for the unit count and enforces the 220.56 floor that the demand can never be less than the sum of the two largest loads, then reports the demand in kVA, kW, and amperes.
How to use this calculator
- Enter each unit of qualifying kitchen equipment as a separate load in kVA (kW at unity power factor). Add a row per piece of equipment.
- Exclude space-heating, ventilating, and air-conditioning equipment; the Table 220.56 demand factors do not apply to those loads.
- Pick the voltage and phase of the kitchen panel for the demand-current readout.
- Read the governing demand load in kVA and kW and the demand amperes. The tool shows whether the demand factor or the two-largest floor governed, along with the connected load, factor, factored load, and two-largest sum.
NEC reference
Demand loads follow NEC 2020 Section 220.56 and Table 220.56 (Demand Factors for Kitchen Equipment, Other Than Dwelling Units). Section 220.56 permits applying the Table 220.56 demand factors to commercial electric cooking equipment, dishwasher booster heaters, water heaters, and other thermostatically controlled or intermittently used kitchen equipment, but requires that the feeder or service demand never be less than the sum of the two largest kitchen equipment loads. Section 220.56 and Table 220.56 are identical in 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 220.56 demand factors
The demand factor is applied to the total connected load of the kitchen equipment. It decreases as the number of units grows, on the diversity assumption that not all equipment runs at full load simultaneously, but never below the sum of the two largest loads.
| Units of equipment | Demand factor |
|---|---|
| 1 | 100% |
| 2 | 100% |
| 3 | 90% |
| 4 | 80% |
| 5 | 70% |
| 6 and over | 65% |
Factors are NEC 2020 Table 220.56. The feeder or service demand is always held to at least the sum of the two largest kitchen equipment loads.
Worked example: six-unit commercial kitchen
A restaurant kitchen has six units of electric cooking equipment totaling 46 kW: a 14 kW range, a 14 kW fryer, a 6 kW oven, and three 4 kW units. There are six units, so the Table 220.56 demand factor is 65%. The factored demand is 46 x 0.65 = 29.9 kW. The two largest loads are 14 + 14 = 28 kW. Because 29.9 kW is greater than the 28 kW floor, the demand factor governs and the kitchen equipment demand is 29.9 kW, or 29,900 / (208 x 1.732) = 83.0 A on a 208 V, 3-phase feeder. This matches the widely published EC&M example.
When the two-largest floor governs
The floor is the reason this tool takes each equipment load rather than a single total. Consider four units of 20, 18, 3, and 3 kVA. The connected load is 44 kVA and the four-unit demand factor is 80%, so the factored demand is 35.2 kVA. But the two largest loads, 20 and 18 kVA, sum to 38 kVA. NEC 220.56 does not allow the demand to fall below that, so the governing demand is 38 kVA, not 35.2 kVA. A whole-building calculator that takes only a unit count and a total load cannot see the individual loads and cannot enforce this floor, which is why very unequal equipment should be run here.
What this tool does not do
- Space-heating, ventilating, and air-conditioning equipment. NEC 220.56 explicitly excludes these; calculate them at their own load, not with the kitchen demand factors.
- Single-unit branch-circuit sizing. This tool gives the feeder or service demand; size the conductor and overcurrent device for an individual appliance with the Wire Size and Breaker Size calculators (NEC 210.19, 240.4, Table 310.16).
- The rest of the building service. Kitchen equipment is one line of an Article 220 Part III calculation; add general lighting, receptacles, and other loads with the Commercial Load Calculator.
- The neutral conductor (NEC 220.61).
Frequently asked questions
Why can the demand be higher than the demand factor suggests?
Because NEC 220.56 sets a floor. When a kitchen has two or three very large units and several small ones, the demand factor applied to the total can fall below the two largest loads running together. The code does not permit that, so the sum of the two largest loads becomes the governing demand.
Do I enter kW or kVA?
Enter each load in kVA. Commercial cooking equipment is largely resistive, so its kW rating is used directly as kVA at unity power factor, the conservative choice that never undersizes the feeder. The demand load is reported in both kVA and kW.
Is this the same as a whole-building load calculation?
No. This computes only the kitchen equipment demand line of NEC Article 220 (Section 220.56). A full commercial service calculation adds general lighting, receptacles, 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 kitchen equipment into the whole building.
- Range / Cooktop Demand Load Calculator: the household cooking demand per NEC Table 220.55, for dwelling units rather than commercial kitchens.
- Service Size Calculator: minimum service disconnect, conductor, and grounding electrode conductor from a known load.
- Wire Size Calculator: the feeder conductor for the kitchen equipment demand, for ampacity and voltage drop.
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