How do I budget for large annual expenses so they don't blow up my month?

Large once-a-year costs, insurance premiums, property taxes, tuition, holiday spending, annual subscriptions, wreck monthly budgets only when treated as surprises. The fix is to convert each annual expense into a monthly obligation by dividing the yearly total by 12 and setting that amount aside in a dedicated sinking fund every month. When a $1,800 premium arrives, the money is already waiting instead of forcing you to raid savings or lean on a card. List every predictable annual and semiannual expense, total the monthly contributions, and treat that combined figure as a fixed bill in your budget. This single habit smooths out the lumpy costs that cause most budget blowups, turning a stressful December or tax season into a non-event.