Skip to content
Book a demo Try the demo MacWindows

Describe a calculation, get a formula

Describe the calculation you want in plain words and AI writes the formula for the cell you are on, explains it, and adds any columns or tabs it needs.

All plansUpdated

You do not need to know a function's name to use it. Click AI beside the formula bar, say what you want to work out, such as "gross margin: revenue minus cost, divided by revenue", and AI proposes the formula for the cell you are on, with a sentence explaining it. You see the formula before anything is written.

Before you start

  • Plans. AI formulas are on every plan.
  • AI needs to be set up: PlexiDesk credits while you are signed in, or your own Anthropic key. See AI credits and where your AI runs.
  • Name your columns if you can, such as Revenue and Cost. AI reads the column names and the first few rows to understand your data.

Get a formula

  1. Click the cell where the answer should go.
  2. Click AI beside the formula bar. The AI · Write a formula panel opens above the grid.
  3. Describe the calculation in the box. It suggests what to write for the cell you are on.
  4. To refer to a column exactly, click its button under the box, such as B: Revenue. The button for the cell you are on, such as D2, adds its reference too.
  5. Click Suggest formula, or press ⌘ Enter on a Mac (Ctrl Enter on Windows). The button reads Thinking… while AI works.
  6. Read the formula and the explanation under it.
  7. Click Apply to write it into the cell, or Re-suggest for another.

The formula goes into the cell you were on, and calculates straight away. Applying it is one step, so one undo takes it back.

When AI needs more room

Sometimes the calculation needs a column or a tab that is not there yet, such as a Margin column. The preview then lists them under Applying will also create:

  • Columns: added at the right of the sheet, with their names.
  • Tab: added at the end of the sheet tabs, with a note of what it is for.

They are only created when you click Apply.

What AI will and will not write

  • AI only offers a formula PlexiiSheets can calculate. If it suggests one that cannot be read, you see a message asking you to describe the calculation differently, and nothing is written.
  • The result is a real formula, so it recalculates when your figures change, and shows an error value if something is wrong, rather than a made-up number.

Write better descriptions

  • Name the columns. "Revenue minus Cost for this row" is clearer than "the profit".
  • Say the shape of the answer. "As a percent", "rounded to two decimals", "only for rows where Status is Done".
  • Say the range if it is not the whole column: "the average of the first ten rows".

Close the panel

Click the × at the top right of the panel, or click AI beside the formula bar again.

Common questions

The formula refers to the wrong cells. Click Re-suggest, or change your description to name the columns. You can also edit the formula after applying it. See Formulas, functions and named ranges.

I want to fill a whole column with the formula. Apply it to the first cell, then drag the small square at the cell's corner down, or double-click it. See Fill, copy and paste.

The panel says no API key is set. AI is not set up yet. Sign in to use PlexiDesk credits, or add your own Anthropic key. See AI settings.

Still need help? Contact support at [email protected].