Further to earlier posts,
attached is an early draft of the Weight & Balance Sheet I've done for the C182 I'm getting checked out on.
It's going to be a bit of an ongoing project - essentially, for the time being, enter actual weight data in cells B53-B59 and it will plot the resultant point on the chart for you, permitting you to see if it falls within the limits. If you go overweight, the total weight cell at B60 will go red. I've been scratting around trying to find an easy way to do the same for the moment cell if you go outside the limits, but that's a bit more complex! I think I'll have to resort to some Visual Basic for that!
Usual caveat applies - this is based on aircraft specific POH / weight and moment info, so requires tailoring for your specific situation.