Column C
First off you'll notice the text "Column C to be used in all cases except as otherwise permitted in Note 3.)", in the title of table 220.55. This makes it simple. You have 2 appliances, so follow that over in the table, and you'll see 11 in Column C. So there you go, you can just use 11 kW. Done.
11,000 W / 240 V = 45.8333 A
So you'll need a 50 ampere breaker, and wire sized appropriately for the load.
Note 3
Note 3 says:
- Over 1 3⁄4 kW through 8 3⁄4 kW. In lieu of the method provided in Column C, it shall be permissible to add the nameplate ratings of all household
cooking appliances rated more than 1 3⁄4 kW but not more than 8 3⁄4 kW and multiply the sum by the demand factors specified in Column A or
Column B for the given number of appliances. Where the rating of cooking appliances falls under both Column A and Column B, the demand
factors for each column shall be applied to the appliances for that column, and the results added together.
Perfect, so instead of just using the value from column C you can do math. Let's step through it.
...it shall be permissible to add the nameplate ratings of all household
cooking appliances rated more than 1 3⁄4 kW but not more than 8 3⁄4 kW...
8.4 kW + 5.0 kW = 13.4 kW
...and multiply the sum by the demand factors specified in Column A or
Column B for the given number of appliances...
Let's check the table again... You have 2 appliances, both between 3 1/2 and 8 3/4 kW. So You'll look at column B, and find 65%.
13.4 kW * 65% = 8.71 kW
8710 W / 240 V = 36.2916 A
So using this method you can use a 40 ampere breaker, and appropriately sized wire. However, keep in mind that if you change the equipment, you'll have to do the calculation again. So while you can use this value, you may have to upgrade the circuit later if you change equipment.
Note 4
I'm not exactly sure how note 4 comes into play, but I think it can be used if this is the only equipment on the branch circuit. Just for fun, let's run through that one too.
- Branch-Circuit Load. It shall be permissible to calculate the branch-circuit load for one range in accordance with Table 220.55. The branch-circuit
load for one wall-mounted oven or one counter-mounted cooking unit shall be the nameplate rating of the appliance. The branch-circuit load
for a counter-mounted cooking unit and not more than two wall-mounted ovens, all supplied from a single branch circuit and located in the same
room, shall be calculated by adding the nameplate rating of the individual appliances and treating this total as equivalent to one range.
You're only concerned with the second half of this note, since you have one counter-mounted cooking unit, and one wall-mounted oven, all supplied by a single branch-circuit, and located in the same room. So you can add the nameplate values, and treat it as a single range.
8.4 kW + 5.0 kW = 13.4 kW
So you can treat the units as a single 13.4 kW range. Check the column C again, this time for a single range. You'll find a value of 8 kW. But wait... The column header says "(Not over 12 kW Rating)". Your range is 13.4 kW. That's bigger than 12 kW. Now you'll have to check note 1
- Over 12 kW through 27 kW ranges all of same rating. For ranges individually rated more than 12 kW but not more than 27 kW, the maximum
demand in Column C shall be increased 5 percent for each additional kilowatt of rating or major fraction thereof by which the rating of individual
ranges exceeds 12 kW.
That's easy enough.
13.4 kW - 8 kW = 5.4 kW
Since .4 is not a "major fraction", you can just use 5 kW. So you'll have to add 5% 5 times.
5% * 5 = 0.25
8000 W * 0.25 = 2000 W
8000 W + 2000 W = 10,000 W
That means you'll have to use 10 kW as your demand.
10,000 W / 240 V = 41.666 A
Which means you can use a 50 ampere breaker, and appropriately size wire.
Best Answer
Your panel needs to be reviewed, carefully.
When you do, you'll have no trouble finding 2 spaces.
It's a quality CH panel, albeit with only 20 spaces. I'm not counting the top 2 spaces in each row, which collectively are the main breaker (100A). Good news is, with this panel arrangement, if you shut off the main breaker, everything is cold except those conspicuous large screws. Which makes it more DIY-friendly than most.
I see seven 240V breakers tying up 14 of 20 spaces. That means all 120V loads in the entire house are served by six 120V breakers, which is pretty compact. I don't believe a house can have seven 240V loads. The usual big four are dryer, A/C, water heater and oven. So I suspect many of these breakers are surplus, particularly since they're off.
The only conceivable reason for this many 240V breakers is having all-electric heat, e.g. baseboard, and if that's the case, forget about an electric range/oven - you just don't have enough service.
Two of those 240V loads are 120/240 split phase. The right side middle rows are a 30A breaker, and looks to have the heavier 10 AWG wire, so it looks to be a dryer. The left side 4th and 5th from the bottom is weird because the white wire is being used as a hot, and the red wire is taped white and used as a neutral (which is illegal to do). That's not right. It might be a multi-wire branch circuit or MWBC, serving two 120V circuits, but I doubt it.
I see a red wire that's taped off, that means there's another black-red-white cable with black and white only being used. That seems weirdly sloppy (why use white for a 240V circuit when you have red) which only worries me more about the quality of work in general.
Even worse, look at the bottom right breaker. It's a 60A breaker but that's NOT a 4 AWG wire. It's either 12 AWG or maybe 10 AWG. That needs a 20A or 30A breaker, respectively. I know exactly what those breakers cost, so no excuse! SHUT IT OFF NOW. NEVER turn it back on. Replace with a 20 or 30A breaker respectively, most hardware stores stock CH220 or CH230. And if it trips, it's supposed to.
Other than that, Mrs. Lincoln...
Go through each circuit in the panel, for two reasons. First, to find any more defects -- after all, I could find two whoppers from a photo. Second, to understand what you do have, so you can either trim or consolidate and free up 2 breaker spaces.
Don't bother hunting down double-stuff (duplex/tandem) CH breakers. Yes, they exist, but you really, really need to re-evaluate this panel, given the large number of defects I've seen from one measly photo. And I think as you do so, you'll free up some space.
Oven/range is straightforward
You simply need a 50A breaker and 6 AWG copper (or 4 AWG aluminum). You could go 40A and 8 AWG, but the difference is only a few bucks, and you'll have a wider selection of ovens/ranges if you go 50A. CH 50A breakers are readily available, not quite as widely stocked as the 20/30s but any big-box should have them. You cannot reuse the 60A breaker.
However, cooking on electric kinda sucks, if you're coming from gas. It's a very annoying learning curve, and a lot of compromises and workarounds. Not recommended.
If you must upgrade the panel
CH is a fine system. One option is get a larger CH panel. However, if you replace the panel, you will need to upgrade most of all of your 6-8 120V loads to AFCI or GFCI or both/combo, and that could get costly. The disadvantage to CH or any 3/4" wide breaker is being smaller, there's less space to cram advanced tech, so they're more expensive or unavailable.
Don't go cheap. This panel is much better than the Homelite and other shlock the local big-box is shoveling. (You can't go by brand anymore, as good brands like Square D and Eaton have bought up cheapie sub-brands.) You have to ask for the good stuff. Get a top-shelf panel from a proper electrical supply. And go really big - bare minimum 42-space, 60-space is not too many. If the main breaker for such a panel is too large, bypass it - put a 100A breaker in the normal spaces and backfeed it (much like is occurring in this panel).