Demand factors on the Texas exam: which loads each one reaches, and which it leaves alone

What a demand factor does

A demand factor is a permission to calculate less. Article 120, where load calculations live in the 2026 edition, carries a handful of them and they all work the same way. You assemble a named group of loads, you meet the conditions the section attaches, and you carry a smaller figure forward into the total.

The reasoning is diversity. A dwelling holds a range, a dryer, a dishwasher, a water heater and a compactor, and the odds of all of them pulling full nameplate at once are low enough that the code lets the service be sized below the sum. One bank item says it plainly: demand factors recognize diversity, and each carries conditions.

Two consequences follow and both get tested. A demand factor lowers a calculated load, so an answer that grew once a factor was applied went wrong earlier. And every factor is scoped to the loads its own section names. The bank offers "it increases the calculated load for safety" as a wrong answer, because the word factor makes people reach for a multiplier above one.

Where they sit in the 2026 book

All of this moved on 1 September 2026, when Texas adopted the 2026 National Electrical Code under 16 TAC 73.100 and the examination began referencing that edition. Load calculations left Article 220 for Article 120, near the front of the book, so a tab set cut for the 2023 edition sends your hand to the wrong page while the clock runs.

The addresses worth carrying:

• 120.13, the branch circuit unit load for dwellings, and 120.41, the feeder and service unit load.
• 120.52 for the small appliance and laundry allowances, and 120.53 for appliances fastened in place.
• 120.54 for a clothes dryer, 120.57 for vehicle supply equipment and 120.60 for noncoincident loads.
• 120.61, the neutral load, which carries two separate reductions of its own.
• 120.80, the scope sentence for that part, and 120.82, the optional dwelling method.

The bank makes an item of that last pair, since landing on the scope sentence under time pressure costs a page turn. Another offers 220.82, the correct address through 2023, as a wrong answer. If your book is still the older one, which edition applies to you is worth settling first.

How the exam asks about them

Our question bank runs to 500 items and 42 sit in the load calculation area, which is where one habit of arithmetic is worth the most marks. Seventeen items mention a demand factor and fifteen of those are load calculation items, so the factor is usually the substance of the question.

The form is consistent. You get a total and a count, or a total and a bracket, and you are asked what that group contributes. Four appliances fastened in place totaling 6,800 volt-amperes contribute 5,100. A general load of 38,000 under the optional method, with the first 10 kVA whole and 40 percent of the remainder, contributes 21,200. The marks sit in knowing which figure to start from.

The wrong answers are built from the ways people start from the wrong figure. Every appliance item carries an option at the full total, for candidates who walked past the factor. The optional method item carries 11,200, a correctly reduced remainder from somebody who left the first 10 kVA out. The dryer item carries 2,940, which is 70 percent of a nameplate that should have been raised to the code minimum first.

The order that decides the answer

Almost every demand factor item turns on one question: what does the factor act on? Get the base right and the arithmetic is trivial. Get it wrong and an option in the list is waiting for your figure.

• The general lighting group. 120.52 lets the small appliance and laundry allowances be included with the general lighting load, so they are added first and the brackets are applied once to the combined subtotal. Reducing the floor area load on its own and adding the allowances at full value inflates the answer, since the portion above the first bracket loses a reduction it was entitled to.
• The dryer. 120.54 sets the load at 5,000 volt-amperes or the nameplate rating, whichever is larger, so a 4,200 volt-ampere nameplate becomes 5,000. Only then does the 70 percent neutral reduction in 120.61 act on it, giving 3,500.
• The range. Same shape: the cooking table produces a demand load and the 70 percent for the neutral acts on that figure, so a range at 8,000 of demand goes on the neutral at 5,600.
• The optional dwelling method. Subtract the first 10 kVA, take 40 percent of what is left, then add the 10 kVA back in. The step that disappears under pressure is the last one, and losing it halves the service.

Which factor reaches which loads

Each reduction owns a group, and the groups stay out of each other.

The 125 percent habit

One sentence in the 2026 edition catches candidates who carry the continuous load multiplier into everything. 120.5(E) states that a load calculation shall not require continuous loads to be calculated at 125 percent. The multiplier still lives where it always did, in the rules that size branch circuits and feeders, with 215.2 putting it on a feeder conductor.

The bank tests that distinction head on, and the wrong answer is the habit: yes, at 125 percent as in every other calculation. A second item works a store's continuous lighting load of 24,000 volt-amperes on a 208Y/120 volt three phase feeder, converts it to 66.6 amperes, then applies the 125 percent from 215.2 to reach 83.3, with one option leaving the multiplier off and another dropping the square root of three.

So two articles do different jobs with the same load. Article 120 produces a load, and the sizing rules turn it into a conductor ampacity and a device rating, which is what feeder sizing does with your answer. The step by step arithmetic on both sides of that line is where the worked calculations live in the question sets, with the section shown beside every step.

The neutral carries its own reductions

120.61 defines the feeder and service neutral load as the maximum unbalance, meaning the largest net calculated load between the neutral and any one ungrounded conductor. A balanced three phase load connected line to line returns nothing through the neutral, so a feeder carrying 60,000 volt-amperes of line to neutral load alongside 40,000 of three phase line to line load has a neutral load of 60,000.

Two reductions sit on top of that figure. Range and dryer loads go on the neutral at 70 percent of the demand already calculated for the ungrounded conductors, because the elements are connected line to line while the controls return on the neutral. Then the portion of the unbalanced load above 200 amperes takes a further 70 percent, so a 260 ampere neutral load lands at 242 while the first 200 stays whole.

That second reduction is withheld in two cases, both about how the neutral behaves. A three wire circuit taken from a four wire wye system falls outside it, and so does the portion of the load that is nonlinear and supplied from a four wire wye system. Harmonic current from each phase lands on that neutral and stays there, so it can carry as much as the ungrounded conductors or more. Service conductor sizing is where the finished figure arrives.

What the error costs

On paper a missed factor costs one item, and there are few to spare. TDLR reported 6,328 attempts at the journeyman calculations portion in fiscal year 2025 against 1,301 passes, a rate of 20.6 percent and the lowest of the four portions the department publishes. A retake is the examination fee again, and the application already on file starts a one year clock under 16 TAC 73.20(b) inside which everything, the examination included, has to be finished.

On the job the same error arrives as equipment. A dwelling whose heating and air conditioning were added together comes out at 165 amperes where 120.60 gives 135, which buys a panelboard and a set of service conductors sized for current nothing in the house will draw. The same happens when a water heater reaches the service calculation already multiplied by 125 percent from its branch circuit rule, which is why the appliance page spends a section on it.

A quieter version is worth naming. A customer asking for room to grow is asking a design question, and 90.1 draws that line: an installation that complies is essentially free from hazard while saying nothing about future expansion. Demand factors reduce a calculated load and stay silent about loads nobody has installed.

What to do before test day

Half an hour of preparation covers a recurring shape on the calculations portion. Four things are worth doing in your book.

• Tab 120.52, 120.53, 120.60 and 120.61 as a block, since a dwelling item usually walks through all four. Texas allows only tabs the publisher supplied, so buy them in and place them early.
• Write the base on each tab. The words "combined subtotal" beside 120.52 and "demand load already calculated" beside 120.61 answer what the item is asking.
• Work one dwelling calculation end to end, floor area through to amperes. The dwelling calculation page walks the same ground with the steps separated out.
• Check the edition on the spine of the book you plan to carry, and check that your continuing education is taught against the same one. 16 TAC 73.25(b)(1) points the four hours at the code as adopted in Texas, and the four hours rule sets out the rest.

Then spend your practice on the base figure alone, saying which section each total belongs to before touching a calculator, because that is the decision the item scores.

Questions people ask

What is a demand factor in the NEC?

It is a permission to calculate a load at less than the sum of its parts, granted by a specific section with conditions attached. Article 120 in the 2026 edition carries several, including the general lighting brackets, the 75 percent for four or more appliances fastened in place under 120.53, the cooking appliance table and the neutral reductions in 120.61. Each one names the group of loads it reaches and leaves everything else alone. The reasoning is diversity, since the equipment in a dwelling rarely runs at full nameplate rating all at once, and the service is sized for what the building actually draws.

Does a demand factor ever increase a calculated load?

No. Every demand factor in the load calculation article reduces the figure it acts on, and an answer that grew after you applied one has gone wrong earlier in the working. The bank offers an increase as a wrong answer precisely because the word factor suggests a multiplier above one. The increases you know about live elsewhere: the 125 percent for continuous loads in the branch circuit and feeder sizing rules, and the floors that raise a small nameplate to a stated minimum, such as the 5,000 volt-amperes a clothes dryer carries under 120.54 whatever its label says.

Which appliances count toward the four that trigger 120.53?

Appliances fastened in place other than electric ranges, clothes dryers, space heating equipment and air conditioning equipment. A dwelling with a dishwasher, a disposal, a water heater and a compactor has four, so the 75 percent applies to that total alone, while the range, dryer and air conditioner are carried at their own values under their own rules. Those categories are held out because each already has a demand treatment somewhere else in the article, and running them through this factor as well would reduce a load that has been reduced once.

Do small appliance and laundry allowances take the lighting demand factor?

Yes. 120.52 permits the small appliance and laundry branch circuit allowances to be included with the general lighting load, which means they are added to the floor area unit load first and the demand brackets are then applied once to the whole subtotal. Doing it the other way around, by reducing the floor area load and adding the allowances at full value afterward, produces a larger answer and loses the reduction those allowances are entitled to. Both routes look reasonable on the page, so the order is worth committing to memory before test day.

Does the load calculation article require continuous loads at 125 percent?

No. 120.5(E) states that load calculations shall not require continuous loads to be calculated at 125 percent, which is one of the genuinely new sentences in the 2026 edition. The multiplier still applies where it always did, in the rules that size branch circuits and feeders, with 215.2 putting it on a feeder conductor. So a store's continuous lighting converts to amperes from the calculated load, and the 125 percent arrives afterward from the sizing rule. Carrying the multiplier into the load calculation itself is how a service comes out one size too large.

How much of the Texas exam is demand factor arithmetic?

Our bank holds 500 items and 42 of them sit in the load calculation area, with fifteen of those turning on a demand factor. On the published blueprint the journeyman calculations portion carries 24 scored items across ten subject areas, and services, feeders and branch circuit calculations together account for most of the places a demand factor can appear. That portion also has the lowest pass rate TDLR publishes, at 20.6 percent for fiscal year 2025, so the arithmetic is where the license is usually won or lost.