Affordable bundle check calculator

The affordable bundle check calculator compares a consumer's chosen quantities of two goods with income and the price of each good. It calculates the bundle's total expenditure, identifies whether the choice lies inside, on, or beyond the budget line, and shows the money left or the shortfall. It also reports spending by good, the percentage of income used, and both budget-line intercepts, making the result useful for economics exercises, planning examples, and quick checks of purchasing choices.

Enter one budget and one consistent set of prices

Start with the consumer's income or spending budget, then enter the unit price and chosen quantity for each of the two goods. Every monetary input must use the same currency and time basis. For example, do not combine monthly income with weekly spending unless you first convert them to a common period.

Quantities may be whole numbers, such as four cinema tickets, or decimals, such as 2.5 kilograms of food. Prices must be greater than zero, while income and quantities may be zero. The calculator treats the entries as a simple two-good budget model: it multiplies each quantity by its price and adds those two expenditures.

No taxes, discounts, borrowing, savings interest, or quantity restrictions are added automatically. If any of those belong in your problem, include them in the effective prices or adjust the available income before running the check. Clear, consistent inputs make the classification directly comparable with the budget-line equation taught in introductory microeconomics.

Read inside, on, and beyond the budget line

The central calculation is total spending: the price of good one times its quantity, plus the price of good two times its quantity. When total spending is below income, the status is affordable; geometrically, the selected point lies inside the feasible budget set. When spending equals income, the status is on budget, meaning the point lies on the budget line and uses all available income.

When spending exceeds income, the status is beyond budget, so the selected point is outside the feasible set at the stated prices and income. The remaining-income result is positive for an affordable bundle, zero on the line, and negative for an over-budget bundle; a negative value therefore expresses the shortfall. The calculator uses a very small scale-aware tolerance when comparing decimal arithmetic.

This prevents values such as tenths, which computers cannot always represent exactly, from turning a mathematically exact equality into an accidental over-budget or under-budget classification.

Use the supporting results to interpret alternatives

Beyond the classification, the result separates spending on each good so you can see which component contributes more to the bundle's cost. The budget-share percentage shows how much of income the bundle consumes. If income is zero and the selected bundle costs more than zero, that percentage is undefined and is reported as null; the beyond-budget status and negative remaining income still give the useful conclusion.

The two maximum-quantity results are the intercepts of the budget line. They answer how much of each good could be purchased if the consumer spent the entire budget on that good and bought none of the other. These intercepts help when sketching the line, comparing price changes, or checking classroom work.

Remember that affordability is not the same as preference or optimality. This calculator verifies feasibility only. It does not know the consumer's utility, tastes, minimum needs, or whether a different affordable bundle would deliver greater satisfaction, so those questions require additional economic analysis.