A simple budget that splits after-tax income into three buckets: 50% for needs (housing, groceries, utilities, insurance, minimum debt payments), 30% for wants (dining out, travel, subscriptions) and 20% for savings and extra debt payments.
Should I use gross or take-home pay?
Take-home pay: what actually reaches your bank account after taxes. If you contribute to a 401(k) from your paycheck, you can count it toward the 20% savings bucket.
What if my needs are more than 50%?
That is common in high-rent cities. Trim the wants bucket first, keep at least some savings going, and look for one large fixed cost (rent, car payment) to bring down over time.