Range Load Calculations Explained: NEC 220.55 and 120.55

Why Range Calculations Trip People Up

Range and cooking-appliance load calculations look intimidating, but they follow a tidy, repeatable pattern once you understand the table you are working from. As the Electrical Code Coach puts it in this lesson, “with practice, time, and patience, you can become a pro, too.” The trick is knowing which column of the table applies to your appliance — and recognising that one of those columns does not behave like the others.

If you are studying from the 2023 or earlier editions of the NEC, you will find this material in Section 220.55 and Table 220.55. If you are on the 2026 or later edition, the same content has moved to Section 120.55 and Table 120.55. Open your physical copy to that table now and follow along — the layout is identical between editions, only the article number changed.

Reading the Table: Number of Ranges and Three Columns

Just like the dryer calculations, the left-hand side of the table lists your number of ranges. From there, you tee off into one of three columns, and choosing the right one depends entirely on the rating of your individual appliance.

• Column A — for individual ranges rated 3.49 kW or less, regardless of how many you have
• Column B — for individual ranges rated between roughly 3.5 kW and 8.75 kW
• Column C — for individual ranges rated 8.75 kW up to 12 kVA

The first step in every one of these problems is the same: find which column your individual range falls into. Everything else follows from that decision.

Columns A and B: Straightforward Demand Factors

Columns A and B work exactly the way you would expect a demand factor to work. You find your number of ranges on the left, cross over to the column, read off the multiplier, and do the maths.

Say you have six 3 kW ranges. Those are Column A appliances. Slide down to six ranges, cross into Column A, and you find a 59% demand factor. Multiply your total connected load by 0.59 and you have your reduced load.

Column B behaves the same way. Imagine six 7 kW ranges — those fall into Column B. Come down to six, cross over, and you land on 43%. Multiply your total load by 0.43 for your new reduced load. Nothing surprising here: find the number, find the multiplier, do the math.

Column C: A Replacement Value, Not a Multiplier

Column C is where people get tripped up, because it does not work like the others.

“Column C is totally different from anything we’ve learned so far. It’s actually just a replacement value.”

Picture six 9 kW ranges. In the old habit, you might take 6 × 9 kW, find a multiplier, and reduce it. That is not how Column C works. Instead, you come down to six ranges, cross into Column C, and read the value — say it says 21. That 21 is not something you multiply. It is your answer: the calculated load is simply 21 kW. No math, no multiplication. Clean and done.

This is the single most important thing to internalise about Column C: the number in the table replaces your load entirely.

Worked Examples From the Lesson

A few quick problems show the pattern in action:

• One 9 kW range, single-family dwelling → Column C. The replacement value stands as the load. No demand factor to apply.
• Three 3 kW ranges → Column A. Total connected load is 3 × 3 = 9 kW, then apply the Column A demand factor for three ranges.
• Two 3.2 kVA cooking appliances → Column A. Total is 2 × 3.2 = 6.4 kVA. The Column A multiplier for two appliances is 75%, so 6.4 × 0.75 = 4.8 kVA.
• One 7 kVA range → Column B. With a single appliance the connected load is done for you, then apply the Column B demand factor of 80%: 7 × 0.80 = 5.6 kVA.

Notice the rhythm every time: find the column, find the total connected load, check for a demand factor, apply it. Column C is the only one where that third step disappears.

Ranges Over 12 kVA: Working With Note 1

Everything above assumes appliances of 12 kVA or less, where you can use the table at face value. When a range exceeds 12 kVA, you have to reach for the notes printed beneath the table — specifically Note 1.

Note 1 covers ranges rated over 12 kVA through 27 kVA of the same rating (for example, five 13 kW ranges all matching). The rule: take the Column C value for your number of ranges and increase it by 5% for each kVA you are over 12.

Here is the worked example for a 14.6 kVA range, single appliance:

1. Confirm the column. It still falls into Column C, with a base value of 8 kVA for one range.
2. Round the rating. Apply the standard major-fraction rule — 0.49 or less rounds down, 0.50 or greater rounds up. 14.6 rounds up to 15 kVA.
3. Find how far over 12 you are. 15 − 12 = 3 kVA over.
4. Calculate the increase. 3 × 5% = 15%.
5. Apply it the fast way. Multiply the Column C base by 1.15: 8 × 1.15 = 9.2 kW.

“When you put that one there, it replaces the eight in the math. It is replacing the eight and then increasing it by that 15%.”

If you prefer the long way, it gives the same answer: 8 × 0.15 = 1.2, then add it back to 8 for 9.2 kW. The 1.15 shortcut just saves you a step. As the coach notes, “this is testing on a master level” — so take your time and work it slowly until the pattern sticks.

Mixed Appliances: A Cooktop Plus Wall Ovens

What about a 3 kVA cooktop with two 4 kVA wall-mounted ovens on one dwelling unit? This looks complicated, but the strategy is simple: treat each appliance by its own column, then marry the totals together.

1. The 3 kVA cooktop is a Column A appliance. Apply its demand factor: 3 × 0.80 = 2.4.
2. The two 4 kVA ovens are Column B appliances, so multiply the connected load by two (giving 8), then apply the Column B factor: 8 × 0.65 = 5.2.
3. Add the demand loads together: 2.4 + 5.2 = 7.6.

Because you are after the total demand, you cannot stop after one appliance — you sum every branch to reach the final figure.

The Bottom Line

Range calculations come down to a handful of disciplined habits:

1. Identify the column first — the individual appliance rating decides everything
2. Remember Column C is a replacement value, not a multiplier
3. Reach for Note 1 whenever a range exceeds 12 kVA, and use the 1 + percentage shortcut
4. For mixed appliances, calculate each column separately and total the results

Get comfortable flipping to Table 220.55 (or 120.55 in the 2026 code), and these problems stop feeling like traps and start feeling routine.

How NEC Mastery Fits Into This

The Electrical Code Coach’s whole method rests on repetition — working problem after problem until the columns, notes, and rounding rules become second nature. That is exactly the kind of practice NEC Mastery is built to deliver.

• 8,000+ exam-style questions give you endless range and load-calculation problems to drill, so Columns A, B, and C become automatic rather than something you second-guess
• Detailed explanations referencing specific NEC articles walk you through each step and cite the exact section — 220.55 or 120.55, plus the over-12-kVA notes — reinforcing where the rules live in your codebook
• Timed mock exams weighted to your exam type let you practise these master-level calculations under real time pressure, so a 14.6 kVA range or a mixed cooktop-and-ovens problem feels routine on exam day

Pair the app with your NEC codebook, work the calculations until the pattern is muscle memory, and you will walk into the exam ready to tee off the right column every time.