How to budget your monthly income

The core principle: plan before the money arrives

All monthly budgeting methods stand on the same principle: every rupiah is given a purpose at the start of the month. Without a plan, the order is always reversed: money is spent first, counted later, and savings only get whatever is left, which is usually zero.

The second key: honestly distinguish needs from wants. Eating is a need; eating at a cafe every day is a want. Internet is a need; upgrading your plan just for streaming is a want. The boundary is yours to set, what matters is that the line exists.

The 50/30/20 method

This popular beginner method was introduced by Elizabeth Warren in the book All Your Worth (2005). Net income is divided into three main buckets:

• 50% needs: food, housing, transportation, bills, and mandatory loan installments.
• 30% wants: socializing, hobbies, entertainment subscriptions, and personal shopping.
• 20% savings and debt: emergency fund, savings targets, and faster debt payoff.

Worked example with a net salary of Rp 4,000,000: Rp 2,000,000 for needs, Rp 1,200,000 for wants, and Rp 800,000 for savings. All three add up cleanly to Rp 4,000,000, with no phantom expenses.

Alternative: The envelope method

The envelope method splits money into smaller, concrete envelopes: a grocery envelope, a gas envelope, and a snack envelope. If an envelope runs empty, that budget is done for the month. This method is ideal for impulsive spenders because the limits feel physical.

The digital version doesn't need paper envelopes. In the Catatku app, you can use multiple Wallets as "envelopes", or set up Budgets per category and track what remains throughout the month.

If your salary barely covers the basics

50/30/20 is a guideline, not a strict rule. If basic needs already take up 70% of your income, don't give up on saving just because 20% feels out of reach. Shrink your wants category first, and start saving from 5% or even Rp 10,000 per day. The percentage can always increase later; the habit is what needs to start first.

Only one thing is non-negotiable: savings must be set aside first. (For more details, check our guide on saving on a small salary).

A budget is only a plan. Records prove it

A budget that is never checked against reality is nothing more than good intentions. Therefore, pair your budget with daily expense tracking: every weekend, compare actual spending with your allocation. Going over budget in one category isn't a failure, it is valuable data for planning next month's budget.

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Questions about this

Is the 50/30/20 method suitable for everyone?

No, and it wasn't designed to be. This method is a starting point. People living in major cities with high living costs might need 60/20/20, while higher earners might use 40/20/40. Feel free to adjust the percentages, as long as all three buckets remain.

My income is irregular. How should I budget it?

Use your average income from your three lowest months as your budget baseline. During months with higher earnings, allocate the extra directly to savings or an emergency fund, rather than inflating your lifestyle.

Which category do debt installments belong to?

The mandatory minimum payments go into Needs because they cannot be postponed. Extra payments to pay off debt faster belong in the 20% category, alongside savings.