How can you avoid common spreadsheet errors?

1 Check formulas

One of the most common sources of spreadsheet errors is incorrect or inconsistent formulas. Formulas are the calculations that you apply to your data, such as sums, averages, percentages, or functions. To avoid formula errors, you should always check the syntax, references, and logic of your formulas before and after entering them. You can use the built-in formula auditing tools in your spreadsheet software to trace errors, evaluate expressions, and highlight dependencies. You can also use relative and absolute references to copy formulas across cells without changing the cell references.

2 Format data

Another common source of spreadsheet errors is improper or inconsistent data formatting. Data formatting is the way you display your data, such as numbers, dates, currencies, or text. To avoid data formatting errors, you should always apply the appropriate format to your data according to its type and purpose. You can use the built-in formatting tools in your spreadsheet software to apply predefined or custom formats to your data. You can also use conditional formatting to highlight data that meets certain criteria, such as outliers, errors, or trends.

3 Validate inputs

A third common source of spreadsheet errors is invalid or inconsistent inputs. Inputs are the data that you enter or import into your spreadsheet, such as values, labels, or ranges. To avoid input errors, you should always validate your inputs before and after entering or importing them. You can use the built-in data validation tools in your spreadsheet software to restrict the type, range, or format of your inputs. You can also use error alerts and input messages to warn or guide users who enter or edit inputs.

4 Document assumptions

A fourth common source of spreadsheet errors is unclear or unrealistic assumptions. Assumptions are the values or conditions that you use to estimate or project your data, such as growth rates, inflation rates, or discount rates. To avoid assumption errors, you should always document your assumptions clearly and explicitly in your spreadsheet. You can use comments, notes, or separate worksheets to explain the source, rationale, and sensitivity of your assumptions. You can also use named ranges or constants to define and update your assumptions easily.

5 Test scenarios

A fifth common source of spreadsheet errors is untested or unexpected scenarios. Scenarios are the different situations or outcomes that you want to analyze or compare in your spreadsheet, such as best case, worst case, or base case. To avoid scenario errors, you should always test your scenarios thoroughly and systematically in your spreadsheet. You can use the built-in scenario manager or what-if analysis tools in your spreadsheet software to create, modify, and switch between scenarios. You can also use data tables or charts to display and compare the results of your scenarios.

6 Review outputs

A sixth common source of spreadsheet errors is inaccurate or misleading outputs. Outputs are the results or reports that you generate from your spreadsheet, such as tables, charts, or dashboards. To avoid output errors, you should always review your outputs carefully and critically in your spreadsheet. You can use the built-in spell check, print preview, and page layout tools in your spreadsheet software to correct and optimize your outputs. You can also use quality control techniques, such as peer review, double-checking, or external verification, to ensure the validity and reliability of your outputs.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?