Guide library
Spreadsheet formula guides for problems that need more than one generated answer
The tools help when you need a formula now. These guides explain the decisions around the formula: when to use a lookup pattern, why #N/A appears, why formulas stop calculating, how to write date criteria, and how to clean imported data before the report breaks.
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Pick the guide that matches the spreadsheet decision
Lookup formulas - 6 min
XLOOKUP vs VLOOKUP: which lookup formula should you use?
Use XLOOKUP for new modern Excel files when collaborators have access to it. Keep VLOOKUP when you maintain older workbooks, need maximum compatibility, or are matching an existing reporting pattern.
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Formula errors - 7 min
#N/A in Excel: how to diagnose lookup errors without guessing
Treat #N/A as a diagnostic signal. Check the lookup value, lookup range, exact-match setting, hidden spaces, data types, and duplicate or missing keys before covering the error with IFERROR.
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Conditional totals - 6 min
SUMIFS by month: date criteria that do not break next year
Use >= first day of the month and < first day of the next month. This handles real dates cleanly and avoids mistakes with month names, year changes, and time values.
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Platform differences - 7 min
Excel vs Google Sheets formulas: differences that matter when copying formulas
Treat Excel and Google Sheets as related but not identical. Check separators, locale, dynamic array behavior, available functions, cross-sheet references, and how many people will edit the file.
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Data cleanup - 7 min
Clean imported spreadsheet data with formulas before you analyze it
Clean imported data in a helper layer before building lookups, totals, or dashboards. Normalize spaces, IDs, dates, labels, and text-number formats so later formulas can stay simple.
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Formula errors - 6 min
Excel formulas not calculating: what to check before rewriting them
Check calculation mode, cell formatting, leading apostrophes, missing equals signs, separator settings, circular references, and copied ranges before replacing a formula that may only need a small setup fix.
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How these guides fit the tools
Use the guide for judgment, then use the tool for the exact formula
A generated formula is most useful when the spreadsheet decision is already clear. The guide library handles the surrounding judgment: compatibility, data cleanup, lookup reliability, date criteria, and whether a missing value should be shown as an error or a clear message.
This keeps the site useful beyond a single generated answer. Each guide has a practical job and links back to the tool only when a custom formula would be the next useful step.
Next pages
Need the formula now?
When the decision is clear and you need output tailored to your columns or platform, move from the guide to the matching tool.
Excel Formula Generator
Start from a plain-English task and get a full Excel formula you can adapt.
Google Sheets Formula Generator
Build Google Sheets formulas with Sheets-first syntax and shared-sheet workflows in mind.
Excel Formula Explainer
Understand what an existing formula does before you edit or replace it.
Fix Excel Formula Errors
Diagnose why a formula is failing and get a safer corrected version to test.