Goal Seek finds the input value that makes a formula hit a target — the classic what-if tool, rebuilt to be fast, honest and private.

HOW IT WORKS
Pick the target cell (it must contain a formula), enter the target value, choose the cell to change, and press "Seek goal". The add-on tries values in your variable cell until the formula meets the target, shows live progress with an iteration log, and lets you keep the solution or restore the original value with one click.

WHY THIS ONE
• Fast: a secant-guided bracketing solver typically needs only a handful of recalculations — most seeks finish in seconds.
• Honest results: if no solution exists you get a clear explanation with the tested range and the closest value found — no cryptic convergence errors. Staircase formulas (SUMIFS, FLOOR, lookup buckets) are detected and reported with the best achievable value.
• Undo-safe by design: the original content of your variable cell (value or formula, dates and formats included) is backed up before the first write and restored on cancel, on failure, and even after an interrupted run.
• Made for real spreadsheets: prefills from your selection, remembers your last inputs per file, understands your locale's number format ("1.234,5" and "1,234.5"), full German and English UI, dark mode, screen-reader friendly.
• Advanced controls when you need them: tolerance, search bounds, starting value and evaluation limit.

PRIVACY FIRST
The add-on requests access to only the spreadsheet you run it in (the non-sensitive spreadsheets.currentonly scope). It has no external servers, makes no network requests, and uses no analytics — no data ever leaves Google Sheets. Details: https://arbeitstyp.de/apps/goal-seek/privacy.html

FREE PLAN
Free for up to 5 runs per day — generous for occasional what-if questions. The daily counter resets at midnight Central European Time.

Google Sheets is a trademark of Google LLC. This add-on is not affiliated with or endorsed by Google.