Budget calculator

How the budget calculator works

A budget is the allocation of your income across spending and saving over a period, usually a month. Enter what comes in and where it goes, and this returns what's left, your savings rate, and what each published budgeting rule says about the same figures.

That last part is the reason this page exists. The rules everyone quotes contradict each other, and they contradict each other for a reason nobody mentions.

The rules disagree, and it's the base that does it

Three ranked calculators, three different answers on housing:

Put a real income through them. Six thousand a month gross, forty-five hundred take-home:

A spread of $675 a month, or $8,100 a year, on identical income. Spend $1,400 on housing and you're comfortably inside calculator.net's rule and clearly outside Ramsey's, without either of them being wrong.

The gap is arithmetic, not disagreement about housing. A percentage of gross and a percentage of take-home are different amounts, and the distance between them grows with your tax rate. Pages quoting these rules rarely say which base they mean, which is how you end up satisfied by one rule and failing another you thought was equivalent.

Where 50/30/20 came from

The 50/30/20 rule splits after-tax income into 50% needs, 30% wants and 20% savings. Elizabeth Warren and her daughter Amelia Warren Tyagi set it out in their 2005 book All Your Worth.

The after-tax base is part of the rule. Applied to gross income it quietly becomes a looser rule than its authors wrote, which is the most common way it gets misused.

Savings targets vary the same way:

On our $6,000 gross and $4,500 take-home, the first two both come to $900. That's a coincidence of a 25% effective tax rate, not agreement. Shift the tax rate and they part company immediately.

India doesn't run the same split

The India SERP is almost entirely small tool sites, and most of them start from 50/30/20 and then move it.

FinToolBaba recommends 56% needs, 19% wants and 18% savings for a renting individual on ₹40,000 a month, and says why: rent runs 20% to 40% of income depending on the city, and 30% to 40% of a mid-level salary in Mumbai or Delhi, which pushes needs above 50% before anything else is counted.

EZTax publishes something different again, described as a typical Indian family budget: housing 35%, transport 10%, education 20%, personal 25%, savings 10%. A 20% education line has no counterpart in any US framework, and its 10% savings figure is half what 50/30/20 asks for.

Multiply, run by the Creador Foundation in Mumbai, ships nine expense categories and recommends no percentages at all. Given the spread above, that's a defensible position.

The needs and wants boundary moves the answer

Reclassifying a single line can shift you a whole band, which is worth knowing before treating any of these percentages as precise.

A car payment is a need for someone commuting where there's no transit and closer to a want for someone with alternatives. Broadband was a want twenty years ago. A gym membership is a want until a doctor makes it something else.

This tool keeps essentials and discretionary spending as separate inputs so you can see how much a reclassification moves your position. Resolving that ambiguity for you would hide it.

What this calculator does not do

It won't tell you which rule to follow, and it won't recommend a split. Every framework here is a published rule of thumb, they disagree with one another, and the right answer depends on circumstances no calculator can see.

It doesn't model irregular income, annual expenses spread across months, or debt payoff order. Nor does it check whether your figures are complete: a budget that balances on paper usually fails on the spending you forgot to list.

Results are arithmetic on your inputs, not financial advice. For decisions about your money, speak to a licensed financial adviser. To work out take-home pay from a gross salary first, the take-home salary calculator covers the Indian case, and the inflation calculator shows what a fixed budget buys in ten years.

Frequently asked questions

What is the 50/30/20 rule? The 50/30/20 rule splits after-tax income into 50 percent for needs, 30 percent for wants and 20 percent for savings and debt paydown. It comes from Elizabeth Warren and Amelia Warren Tyagi's 2005 book All Your Worth, and the after-tax base is part of the rule itself, not an implementation detail.

How much should I spend on housing? The published rules disagree, and they disagree partly because they measure against different things. Ramsey puts housing at 25 percent or less of take-home pay, calculator.net at no more than 30 percent of gross income, and EZTax describes a typical Indian family budget with housing at 35 percent. On 6,000 gross and 4,500 take-home those work out at 1,125, 1,800 and 1,575 a month, a spread of 675.

Why do budgeting rules give different answers? Mostly because they apply to different bases and rarely say so. A rule quoted as a percentage of gross income and one quoted as a percentage of take-home pay produce very different amounts, and the gap widens with your tax rate. Comparing two rules without checking which base each uses is the most common way to conclude your budget is fine when one of them says it is not.

What is a good savings rate? The rules again differ: 20 percent of after-tax income under 50/30/20, 15 percent or higher of gross income per calculator.net, and a 10 percent minimum with 20 percent given as the healthier target per MoneyManagement.org. At a 25 percent effective tax rate, 20 percent of take-home and 15 percent of gross happen to be the same amount, which is a coincidence of that rate and not a rule.

Do the same rules work outside the US? Not cleanly. India-facing planners run the needs bucket higher, with FinToolBaba recommending 56 percent needs, 19 percent wants and 18 percent savings at a 40,000 rupee take-home, justified by rent taking 20 to 40 percent of income depending on city and 30 to 40 percent of a mid-level salary in Mumbai or Delhi. EZTax publishes a different Indian split again, with a 20 percent education line that has no counterpart in any US framework.

Should the percentages apply to gross or take-home pay? Whichever the rule you are following specifies, and this tool asks for both so it can apply each one correctly. The 50/30/20 rule is written against after-tax income, Ramsey against take-home pay, and calculator.net against gross. Applying a take-home rule to a gross figure makes your budget look healthier than the rule intends.

What does this calculator not tell me? Which split to follow. Every framework here is a published rule of thumb, they contradict one another, and choosing between them depends on circumstances a calculator cannot see. The tool shows what each rule implies for your numbers and leaves the choice with you.

What counts as a need rather than a want? The boundary is genuinely fuzzy and moves the answer a lot. Housing, transport, food, utilities, minimum debt payments, insurance and childcare are usually needs; dining out, entertainment, subscriptions and travel are usually wants. A car payment sits in needs for a commuter and closer to wants for someone with transit alternatives, and reclassifying one line can move you a full band.

Sources

• Ramsey budget calculator, the source for housing at 25% of take-home and the zero-based method
• calculator.net budget calculator, the source for the gross-income thresholds
• Transamerica on the 50/30/20 rule, attributing it to All Your Worth (2005) and the after-tax base
• MoneyManagement.org budget calculator, the source for the 10% minimum and 20% target
• FinToolBaba income and expense planner, the source for the India-adjusted split and the rent figures
• EZTax personal budget calculator, the source for the alternative India split