Variable expenses are those expenses that track directly with sales. If sales stop they stop. These are expenses like supplies used to support in the making of your product or doing your service. Such things as shipping cost for raw materials for your product or service. If you have no sales then you're not going to be purchasing materials so your shipping cost for those materials will stop as well. As an example, if you have a lawn mowing business and there are no lawns to mow, then you wouldn't be buying gasoline to travel to your lawn mowing site. These kinds of things are variable expenses. If you're producing a product, it would include supplies used to produce that product like sand paper, glue, finishing materials, cutting tools, etc.
Here are the steps you would need to take. First, you would need to know all your current business numbers. This will be the basis for the plan. You're going to need to know: 1. What your current average monthly sales are 2. What your current average monthly material cost is 3. What your current average monthly labor cost is 4. What your current average monthly fixed expenses are 5. What your current average monthly variable expenses are 6. What your average number of transactions per customer per month are 7. What your average dollar sale per transaction is 8. What your average monthly profit is 9. What your average monthly profit margin is 10. And what % capacity your business is at right now Second, decide what you want your salary to be Third, determine how many years in the future you want to plan for Fourth, you will need to know: 1. What % is your material cost of sales? 2. What % is your labor cost of sales? 3. And what % is your variable expense of sales?