Quick Hits

⚡ Quick Hit: Big Ranges Get a Kilowatt-by-Kilowatt Bump

NEC Article 120 — “Load Calcs Won't Kill You” 🔌⚡

Episode 19 — 120.55 Electric Cooking Appliances

🍳 THE QUICK HIT

Got a household electric range rated above 12 kW?

Table 120.55's Column C maximum demand may not be the final number.

The notes to the table provide a method for increasing the Column C maximum demand based on how far the range rating goes above the 12 kW baseline.

And there's a separate method when the ranges have different ratings.

📈 NOTE 1 — SAME-RATED RANGES OVER 12 kW

When all ranges are individually rated more than 12 kW but not more than 27 kW, the Column C maximum demand is increased.

THE FORMULA

Increase the Column C maximum demand by:

5% for each additional kW — or major fraction of a kW — above 12 kW

Think of 12 kW as the starting line.

Every additional kW above that line adds another 5%.

🧮 EXAMPLE

A range is rated at:

15 kW

First determine how far above 12 kW it is:

15 − 12 = 3 kW

Then:

3 × 5% = 15%

Therefore, the applicable Column C maximum demand is increased by:

15%

⚠️ This is an increase to the Column C maximum demand, not a statement that the appliance's actual nameplate load is simply multiplied by 115%.

🔀 NOTE 2 — DIFFERENT-RATED RANGES OVER 8¾ kW

What happens when the ranges don't all have the same rating?

A different method applies when there are ranges of different ratings, with each range rated over 8¾ kW, subject to the stated limits.

STEP 1 — ADD THE RATINGS

Add the ratings of all the ranges.

For this calculation, any range rated below 12 kW is treated as 12 kW.

STEP 2 — FIND THE AVERAGE

Divide the total by the number of ranges.

This gives you the average range rating.

STEP 3 — COMPARE TO 12 kW

Determine how many kW the average rating exceeds 12 kW.

STEP 4 — APPLY THE 5% INCREASE

Increase the Column C maximum demand by 5% for each additional kW — or major fraction of a kW — above 12 kW.

🧠 WHY THE TWO METHODS?

The notes recognize two different situations:

Same-rated ranges

Look at the individual rating.

Different-rated ranges

Calculate an average rating first.

Then determine the applicable increase.

🎯 TEST YOURSELF

Per Note 1, if a range is individually rated at:

15 kW

By how much should the Column C maximum demand be increased?

A) 5% total, regardless of rating

B) 15% — 5% × 3 kW over the 12 kW baseline

C) 27% — matching the 27 kW ceiling

D) No increase — 15 kW doesn't qualify

👇 What's your answer?

🧮 SHOW YOUR MATH

Range rating:

15 kW

Baseline:

12 kW

Difference:

15 − 12 = 3 kW

Increase:

3 × 5% = 15%

⚡ RESULT

15% increase to the Column C maximum demand

✅ ANSWER

B) 15%

The range is 3 kW above the 12 kW baseline.

3 × 5% = 15%

🔑 REMEMBER

12 kW = baseline

Each additional kW = +5%

15 kW = +15%

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🧭 QUICK HIT NAVIGATION

← Back to Article 120 Quick Hits

← Back to 2026 NEC Quick Hits

← Episode 18 — Cooking Appliances: The Base Rule

→ Episode 20 — Cooking Appliance Notes

📌 SOURCE NOTE

The actual Table 120.55 Column A/B/C demand-factor values are not reproduced here because the complete table was not included in the source material available for this Quick Hit.

This page explains the adjustment methodology contained in the table notes without fabricating the missing Column C values.

For the exact demand-factor values, consult the official NEC and the complete Table 120.55.

⚠️ EDUCATIONAL NOTICE

This Quick Hit is an educational explanation based on the author's understanding of the NEC. It is not a substitute for the official NEC, applicable local amendments, manufacturer instructions, or the determination of the Authority Having Jurisdiction (AHJ).

Always verify the requirements applicable to your specific installation.

The National Electrical Code® and NEC® are registered trademarks of NFPA. JoshTheSparky.com is not affiliated with, sponsored by, or endorsed by NFPA.