Free online solver
Optimise a spreadsheet without leaving your browser.
Paste a model from Excel or Google Sheets, or build one directly in the grid. Plumline interprets your formulas, recalculates the objective and constraints, and shows whether every limit is satisfied — within its solving limits. Nothing is uploaded, nothing is stored, and there is nothing to install.
Paste from Excel or Sheets, or start typing below.
Yellow cells are the quantities to decide. Copy a table from Excel or Google Sheets and paste it into any cell — Plumline expands the grid automatically. Put an operator (≤, ≥, =) and a number to the right of a limit. Edit anything and solve again.
Use this for quantities that cannot be fractional, such as people, vehicles or projects.
Auto-detect reads commas and semicolons from your sheet. Set this if a decimal comma is misread.
Your answer will appear here, checked against your own numbers.
How it reads your grid
Plumline looks for one cell that totals the others: that becomes the goal. The cells that total feeds into, and that are currently empty or zero, become the quantities it can change. Any row with a comparison operator and a number becomes a limit. It uses the labels in your first column to name everything, so the answer reads in plain words.
It solves continuous, integer, binary and mixed-integer linear problems: production, purchasing, blending, staffing, transport, budgets, project selection and loading. Use Variable settings to make a decision whole or 0/1 and to set its minimum and maximum. It does not solve genuinely non-linear ones, such as a quantity multiplied by another quantity, and points you to the cell causing the problem.