Include all variable expenses now, car maintenance, electricity, heating, these can vary throughout the year you need to calculate them and come up with an average monthly amount. None essential expenses like eating out coffee at Starbucks, weekend getaways, extravagant vacations, fancy clothing, motorcycles, ATV's, if you use them, write them down, realize these are wants, not needs. Now total these all up, fixed expenses, variable expenses, and non_essential expenses,there you now have your total expenses.
First, track your spending and expenses for the next 30 days. You can begin by recording all your purchases on a weekly expense report worksheet that you fill out each day. Save your receipts from each purchase and then record a description of the purchase, the amount, its category, and how you made the purchase; whether by cash, check, or credit card.