Corner Point Calculator

Solve a two-variable linear programming problem by evaluating the feasible region's corner points.

Linear programming corner point method
Enter an objective and two less-than-or-equal constraints.

The calculator also applies the nonnegativity conditions x greater than or equal to zero and y greater than or equal to zero.

About the corner point method

Linear programming optimizes a linear objective while respecting linear constraints. In a problem with two decision variables, each inequality represents a half-plane on a coordinate graph. Their shared area is the feasible region. When that region is bounded and nonempty, a maximum or minimum objective value occurs at one or more of its corner points, also called vertices or extreme points. The corner point method uses this fact to replace a continuous search with a finite set of evaluations. This calculator accepts an objective of the form cx times x plus cy times y and two constraints of the form ax times x plus by times y less than or equal to a limit. It also enforces standard nonnegativity conditions, so x and y cannot be negative. It constructs candidate vertices from the origin, intercepts on both coordinate axes, and the intersection of the two constraint boundary lines. Candidates that violate either inequality are removed. After finding feasible corners, the calculator substitutes every point into the objective function. For maximization it keeps the largest value; for minimization it keeps the smallest. The displayed corner list lets you verify the comparison. If two adjacent vertices produce the same best value, every point on the segment joining them is also optimal, even though this compact result names one of those vertices. The graphical method is especially useful for production planning, resource allocation, diet models, and introductory operations research. Decision variables can represent quantities of products, hours of work, or amounts of material. Constraint coefficients describe how each decision consumes a limited resource, while objective coefficients represent profit, cost, time, or another performance measure. A correct model matters as much as arithmetic. Confirm that every constraint uses compatible units and that the inequality direction matches the practical limit. This calculator specifically handles two less-than-or-equal constraints plus nonnegativity. Problems containing greater-than-or-equal or equality constraints may need algebraic conversion and can create feasible regions not represented by this input form. The corner point method is not a substitute for the simplex method on large models, but it makes the underlying geometry clear. It also provides a quick check for hand-drawn feasible regions. Decimal results are rounded to six places for readability. If coefficients produce exact fractions, retain those fractions in formal work to avoid accumulating rounding error.

Corner point examples

ProblemOptimal pointObjective value
Max 3x + 2y; x + y at most 4; x at most 2(2, 2)10
Max x + 4y; x + y at most 5; 2x + y at most 8(0, 5)20
Max 2x + y; x + y at most 6; x + 2y at most 8(6, 0)12

How to find the optimal corner

  1. Choose whether the objective function should be maximized or minimized.
  2. Enter the x and y coefficients from the objective function.
  3. Enter both coefficients and the right-side limit for each less-than-or-equal constraint.
  4. Select Find optimal corner to generate and test the feasible vertices.
  5. Compare the optimal point, objective value, and complete feasible corner list.

Frequently asked questions

Why does an optimum occur at a corner point?

A linear objective has parallel level lines, and moving one across a convex feasible polygon reaches its extreme value at a boundary vertex or edge. Therefore checking all vertices is sufficient for a bounded feasible region.

What constraints does this calculator support?

It supports two linear less-than-or-equal constraints in two variables and automatically requires both variables to be nonnegative. Other inequality forms must be converted before entry when that conversion preserves the intended region.

What if two corners have the same optimal value?

The calculator reports one optimal corner. When adjacent corners tie, every point along their connecting feasible edge is also optimal.

Can a linear program have no feasible solution?

Yes, constraints can contradict one another so no point satisfies all of them. This input format often includes the origin when limits are nonnegative, but different constraint directions can produce infeasibility.

How are candidate corners generated?

The calculator tests the origin, valid axis intercepts, and the intersection of the two boundary lines. It then discards every point outside the nonnegative feasible region.