Variable expenses
Costs that change from month to month, like groceries, gas, dining out and electricity.
Variable expenses move up and down based on your choices and the season. Groceries, gas, eating out, shopping and utility bills are common ones.
Because they change, they are the easiest place to find quick savings and the easiest place to overspend. Tracking them for a month or two shows your real average, which makes a better budget number than a guess.
Example
If your groceries cost $380, $420 and $440 over 3 months, your average is ($380 + $420 + $440) ÷ 3 = $1,240 ÷ 3 = about $413 a month.