Optimize sheet performance

Optimize sheet performance in Google Sheets — with three ready prompts, from the immediate task to the lasting pattern.

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3 ready prompts

Written for the moment this actually comes up.

Execute — do the immediate task

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Speed up the sales forecast sheet so the team can work today. Remove the volatile formulas in sheet…
Speed up the sales forecast sheet so the team can work today. Remove the volatile formulas in sheet Forecast that recalculate on every edit, replace ARRAYFORMULA ranges that reference entire columns with bounded ranges A2:A500, and move the historical lookup into a static sheet called History that updates nightly. Confirm the sheet reloads under five seconds for Emma on her laptop before EOD.

Improve — make it easier to accept

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Before I hand the forecast to operations, make it fast and reviewable. Identify formulas with…
Before I hand the forecast to operations, make it fast and reviewable. Identify formulas with INDIRECT, OFFSET or open-ended ranges and convert them to index-match with fixed ranges. Add values-only copies of historical data for rows older than 12 months and use helper columns to avoid repeated VLOOKUPs. Flag any scripts that trigger onChange and note where recalculation still slows the sheet.

Decide — diagnose the stuck moment

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When anyone edits a cell in the top section of the forecast, the sheet freezes for 20–30 seconds…

The sheet freezes every time someone types a number

When anyone edits a cell in the top section of the forecast, the sheet freezes for 20–30 seconds and people stop updating forecasts; I can’t tell if it’s a single heavy formula, an onChange script, or many volatile ranges. What diagnostics should I run quickly to identify the culprit and what is the fastest remediation so the team can edit without freezing?

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Other spreadsheet work people do in Google Sheets.

Every task here came from the work, not from a feature list — which is why the prompts name what you want done and never the button that does it. The tool changes; the work does not.
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