Simplex Tableau Pivot Operations Calculator

Build accurate pivot steps from any tableau. Review normalized rows, reduced costs, and RHS changes. Learn each transformation with neat outputs and useful exports.

Calculator

Build and Pivot a Simplex Tableau

Use manual mode to choose any pivot location. Use automatic mode to suggest the entering column from the most negative objective coefficient and the leaving row from the minimum positive ratio.

Comma separated. Last label is the objective row.
Comma separated. Last label is RHS.
Row C1 C2 C3 C4 C5 RHS
R1
R2
R3
Z
Formula Used

Simplex Tableau Pivot Formulas

1) Normalize the pivot row
New pivot row = Old pivot row ÷ pivot element
2) Eliminate the pivot column in all other rows
New row i = Old row i − (entry in pivot column of row i × new pivot row)
3) Ratio test for leaving row
Ratio = RHS ÷ pivot column coefficient, using only positive pivot column entries

The calculator treats the last row as the objective row and the last column as the RHS column. In auto mode, the entering column is the most negative coefficient in the objective row. The leaving row is the smallest positive ratio from the eligible constraints.

How to Use This Calculator

Steps to Perform a Pivot

  1. Enter the number of constraint rows and the number of non-RHS columns.
  2. Optionally rename rows and columns with comma-separated labels.
  3. Fill the tableau values. The last row is the objective row.
  4. Select manual mode if you already know the pivot row and pivot column.
  5. Select auto mode if you want the calculator to suggest a valid simplex pivot.
  6. Press Calculate Pivot to normalize the pivot row and update the tableau.
  7. Review the ratio test, the new tableau, and the RHS comparison chart.
  8. Use the CSV or PDF buttons to export the result section.
Example Data Table

Worked Example Input

This example is the same one loaded by the example button. It uses three constraints, five non-RHS columns, and one objective row.

Row x1 x2 s1 s2 s3 RHS
R1 2 1 1 0 0 18
R2 2 3 0 1 0 42
R3 3 1 0 0 1 24
Z -3 -2 0 0 0 0

For this example, a common first pivot is at row R3 and column x1, because x1 is the most negative objective coefficient and 24 ÷ 3 gives the minimum positive ratio.

FAQs

Frequently Asked Questions

1. What does a pivot operation do in the simplex method?

A pivot operation changes the tableau basis. It makes the pivot element become 1 and turns every other entry in that pivot column into 0. This updates the system while preserving equivalence, allowing the algorithm to move toward a better feasible solution.

2. How is the entering variable chosen?

For a standard maximization tableau, the entering variable usually comes from the most negative coefficient in the objective row, excluding the RHS column. That column suggests the strongest immediate improvement in the objective value.

3. How is the leaving variable chosen?

The leaving row is found with the minimum positive ratio test. Divide each eligible RHS by its positive pivot-column coefficient. The smallest positive ratio identifies the row that leaves the basis while keeping feasibility.

4. Why are zero or negative pivot-column entries ignored in the ratio test?

They are ignored because dividing by zero is invalid, and negative or zero coefficients do not produce the required bound for maintaining feasibility in the next basic solution. Only positive coefficients can define a valid leaving row.

5. Can I use manual pivot selection?

Yes. Manual mode is useful for study, classroom checks, and verifying homework. You can choose any constraint row and any non-RHS column. The calculator then performs the exact row operations for that selected pivot location.

6. What does the RHS graph show?

The graph compares the right-hand-side values for each constraint row before and after the pivot. It helps you see how the basis update changes the current basic solution and whether the transformed tableau shifts resource levels significantly.

7. Why does the calculator treat the last row and last column specially?

The last row is assumed to be the objective row, and the last column is assumed to be the RHS column. This is the standard tableau structure used in many simplex examples and classroom formulations.

8. Does one pivot solve the whole linear programming problem?

No. One pivot performs one simplex iteration. Many problems require several pivots before the objective row satisfies the stopping condition. This calculator focuses on one pivot step so you can inspect the transformation clearly.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.