Build your monthly budget using the 50/30/20 rule and find your surplus or deficit.
Popularized by Senator Elizabeth Warren in her book "All Your Worth," the 50/30/20 rule provides a simple framework for managing your money:
If you live in an expensive city like New York or San Francisco, your housing alone may consume 40–50% of take-home pay. In that case, cut from wants rather than savings — and look at strategies like having roommates or a longer commute to reduce housing costs.
Another approach: assign every dollar a job until your budget equals zero (income - all expenses - savings = 0). This is more detailed but can be more effective for people who want tight control over every category.