Completely off the cuff I'd say you are cutting it close right now.

Remember, electronics do not draw very much contrary to popular belief. So a new TV and an Xbox will not push your usage over the edge. A pool running constantly, a spa, electric heat, motors, an electric dryer, lots of incandescent lighting, etc, are all the type of things that will increase your usage noticeably.

If you are now doing a major renovation, and considering the large size of your home, I'd say this is a good time to seriously consider an upgrade to 320/400 amps.

Thanks petey racer. I assume that if I told you I forgot to mention we also had two electric water heaters, you would say we are cutting it even closer?

With the hot water, you are cutting close. Now if you told me you lived in a cool climate and had any type of electric heat you would be definitely over loaded. There is a milbank meter base (about 350 amp) that has two 200 amp disconnects, which would allow you to just replace the service entrance meter and service drop and then add a second 200 amp panel which would help shed load from the existing. If you were to add a hot tub of some sort or a sauna, you would be toast. Your biggest load will be around the holidays or on the hottest day of the year, which is a very bad time to blow a main breaker.

Have you ever tripped your main breaker?

Rather than us guessing, why don't you take an inventory of the major appliances, along with their wattage and voltage rating (120/240). The wattage will be on a plate. If you can't find it or it's not easily accessible, Google it.

Major appliances would be those things that use electricity to heat or run a large motor. Stove, water heaters, pool motors, spas, clothes dryers, electric heaters, air conditioners etc. are all in this category.

Doing the math would take a few hours and is certainly cheaper than a new service.

A better way to do this is just to hire someone with an amp-clamp to measure the current on each leg of the main with a representative number of appliances working at the same time. A more valid test would be to record use over a day or two with a meter that records and charts the data (fluke 289, for example. Just getting the peaks will be deceptive because of motor start-ups). You want to be less than 80% of your breaker rating.

If you are close, you should consider ways of reducing energy use - it could be a lot cheaper than a new panel.
If you have a lot of incandescent lights, replace the bulbs with energy saving florescent bulbs, for example. Consider high efficiency AC units too. You might even consider changing your water heaters to gas (perhaps gas tankless), since it's available.

Sorry Jake, that's simply not how it's done. The actual usage and adding up wattage of the appliances is still only a guess.

A demand load calculation is the only true way to tell. That said, and after doing a few of them myself, I still think an upgrade to 320/400 would be in his best interest.
Reducing consumption is all well and good, but the OP says this is in the context of a "major renovation" of a 4600 sq/ft house.

Petey,

The point is that we are guessing and doing some math gets you a lot closer. Putting a meter on it and testing it with a reasonable combination of loads gets us even closer.

Reducing consumption is potentially cheaper in the short run, and it obviously can be less expensive in the long run too.

On the other hand, if money isn't an issue - then go for it. (But why ask about it on an electrical forum)