I packed nearly 12 days worth of food into a 650 cubic inch Bearikade Weekender for a recent trip I was forced to abort due to injury. I endorse all of the advice you have received here so far. In addition I would add a few recommendations:

First, when you repackage use sandwich bags or 1 mil plastic bags rather than the standard, thicker, heavier snack or freezer bag. they weigh less and, if you invest in a heat sealer (about $30), can be custom fitted to the contents.

Second, rather than rehydrating your meals in a freezer bag, get a three-cup, snap-top, dishwasher-safe leftover container and make a cozy for it. Mine is a Ziplock that weighs a bit over an ounce. This is less than the weight of three freezer bags. The one mil container bags are virtually weightless.

Third, when you pack, punch a pin hole in each bag to allow air to escape as you carefully place your food into the bear can in layers of food of a day per layer. The less unpacking and repacking you do the less frustration you will face. The pin hole lets any included air escape and doesn't seem to affect food quality over a week or two. Press down hard on the stuff you have previously put in the can to help push out the air.

Fourth, be aware that almost everyone packs too much food for a given trip. Most of us have a diminished appetite for the first few days. Acknowledge that when planning meals. And, it doesn't hurt to finish dinner a bit hungry. High calorie density stuff like nuts and sausage should be a big part of the day's eating; dinner should rehydrate and recharge you not provide the day's calories. Sugary drinks are compact and have about 100 calories per ounce but can raise cain with your blood sugar levels; just drink plain water.

Fifth, don't pack the first day's food in the canister.

Sixth. Unless you are unusually lean you are carrying some adipose tissue with you. This provides about 3500 calories per pound. Rely on using a bit of that. If you loose two pounds of fat weight on your trip you have provided 7000 calories (around two days worth) that don't have to be squeezed into your bear can.

Have a great trip.