EXPLORE · ADJUST · EXPLAIN

Raise utility until the budget just reaches it

Move through indifference curves in 2D, or move a horizontal utility slice through the 3D surface.

Preferences & budget

Utility family

Preference weight · α

Income · m

Use the sliders for broad changes, or type an exact value such as 125.5.

Price of x · pₓ

Price of y · pᵧ

Selected utility level · ū

Raise the curve until no higher level is affordable. In 3D, this moves the orange height plane.

Automatic rescaling

View window · axis controls

The x and y axes share one range. Editing these bounds turns off automatic rescaling.

Maximum x and y

Utility height range

Budget and indifference curves

The x and y axes rescale together, keeping the same unit scale.

Selected indifference curve / heightū = 6

BudgetSelected utility levelOther utility levels

The best affordable indifference curve just touches the budget at a tangency, a kink, or a corner. Higher utility means a more preferred bundle; utility numbers themselves are only a ranking.

The consumer’s problem

Preferences

U(x,y)=x^{\alpha}y^{1-\alpha}

Choose an affordable bundle

\begin{aligned}\max_{x,y\ge0}\quad &U(x,y)\\\text{subject to}\quad &p_xx+p_yy\le m\end{aligned}

Explore first, then check.

The graph stays live. Worked calculations and the optimal bundle appear only when you ask for them.