[Jeff n Susan]

You need to determine the wattage required to run each of your appliances. Total them up for a total wattage draw, then make sure your inverter will handle the load. For example, you have a total draw of 1800 watts. I would probably go with a 3000 watt inverter to make sure I have enough current. Coffee brewers love wattage!
The time under the load (How long it will support the load)depends on the amp hours of your battery bank. Hope this helps!