Custom formula-based rules in Google Sheets - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a custom formula-based rule in Google Sheets conditional formatting?

It is a rule where you write your own formula to decide which cells get special formatting. The formula must return TRUE for cells to be formatted.

beginner

How do you write a custom formula to highlight cells in column A that are greater than 100?

Use the formula =A1>100 in the custom formula rule. This checks each cell in column A if it is more than 100.

intermediate

Why do you use absolute and relative references carefully in custom formulas?

Because the formula applies to many cells, relative references change for each cell, while absolute references stay fixed. This controls which cells the formula checks.

beginner

What happens if your custom formula returns FALSE for a cell in conditional formatting?

That cell will not get the special formatting. Only cells where the formula returns TRUE are formatted.

intermediate

Give an example of a custom formula to highlight rows where the value in column B is empty.

Use =ISBLANK($B1). The dollar sign fixes column B, and the row number adjusts for each row.

What must a custom formula return to apply formatting to a cell?

A FALSE

B TRUE

C A number

D Text

The formula must return TRUE for the formatting to apply.

Which formula highlights cells in column C that are less than 50?

A =$C1<50

B =C$1<50

C =C1<50

D =$C$1<50

=$C1<50 fixes the column C but lets the row change for each cell.

What does the dollar sign ($) do in a custom formula reference?

A Changes the cell color

B Makes the reference relative

C Deletes the reference

D Makes the reference absolute (fixed)

The $ fixes the column or row so it does not change when applied to other cells.

If you want to highlight entire rows where column A is 'Yes', which formula is correct?

A =A$1="Yes"

B =A1="Yes"

C =$A1="Yes"

D =$A$1="Yes"

=$A1="Yes" fixes column A but lets the row number change for each row.

Can you use functions like ISBLANK() in custom formula rules?

A Yes, to check conditions like empty cells

B No, only simple comparisons

C Only in Excel, not Google Sheets

D Only with numbers

Functions like ISBLANK() work well in custom formulas to check cell conditions.

Explain how to create a custom formula-based rule to highlight cells in a column based on a condition.

Think about how the formula checks each cell and returns TRUE or FALSE.

Describe the role of absolute and relative references in custom formula rules and why they matter.

Consider how the formula moves when applied to many cells.

Practice

1. What does a custom formula in Google Sheets conditional formatting need to return to apply the format?

easy

A. A text string

B. FALSE

C. A number

D. TRUE

Solution

1. Step 1: Understand conditional formatting rules

   Custom formulas in conditional formatting must evaluate to TRUE or FALSE to decide if formatting applies.

2. Step 2: Identify the required return value

   Only when the formula returns TRUE does the formatting get applied to the cell.

3. Final Answer:

   TRUE -> Option D

4. Quick Check:

   Formula must return TRUE [OK]

Hint: Remember: TRUE applies formatting, FALSE does not [OK]

Common Mistakes:

• Thinking the formula should return FALSE to apply formatting
• Returning numbers instead of TRUE/FALSE
• Returning text strings instead of logical values

2. Which of these is the correct syntax for a custom formula to highlight cells in column A that are greater than 100?

easy

A. =A1>100

B. =A>100

C. =A$1>100

D. =1A>100

Solution

1. Step 1: Understand cell references in custom formulas

   Formulas must use a relative reference to the first cell in the range, here A1.

2. Step 2: Check each option's syntax

   =A1>100 is correct; =A>100 is invalid because column alone is not a valid reference; =A$1>100 fixes row but not needed here; =1A>100 is invalid syntax.

3. Final Answer:

   =A1>100 -> Option A

4. Quick Check:

   Use relative cell reference like A1 [OK]

Hint: Use the first cell's reference in your formula [OK]

Common Mistakes:

• Using only column letter without row number
• Using invalid cell references like 1A
• Fixing row or column unnecessarily

3. Given the range B2:B5 selected, what cells will be highlighted by the custom formula =B2>50?

medium

A. Only B2 if its value is greater than 50

B. All cells B2 to B5 where each cell's value is greater than 50

C. Only B5 if its value is greater than 50

D. No cells because formula only checks B2

Solution

1. Step 1: Understand relative references in custom formulas

   The formula is written relative to the first cell B2, so it adjusts for each cell in the range.

2. Step 2: Apply formula to each cell in B2:B5

   For B3, formula becomes B3>50; for B4, B4>50; for B5, B5>50. So all cells in the range are checked individually.

3. Final Answer:

   All cells B2 to B5 where each cell's value is greater than 50 -> Option B

4. Quick Check:

   Formula adjusts per cell in range [OK]

Hint: Formula adjusts relative to each cell in the range [OK]

Common Mistakes:

• Thinking formula only checks the first cell
• Assuming formula is fixed to B2 only
• Not understanding relative references

4. You want to highlight rows where the value in column C is "Done". You select range A2:D10 and enter the formula =C2="Done". But no cells get highlighted. What is the problem?

medium

A. Formula should be =$C2="Done" to fix column C

B. Formula should be =C$2="Done" to fix row 2

C. Formula should use absolute reference $C$2

D. Formula should be =C2=Done without quotes

Solution

1. Step 1: Understand how to fix column in custom formulas

   To apply the formula across rows but always check column C, fix the column with $ but keep row relative.

2. Step 2: Correct the formula

   =$C2="Done" fixes column C, so for each row it checks the correct cell in column C.

3. Final Answer:

   =$C2="Done" -> Option A

4. Quick Check:

   Fix column with $ to check same column [OK]

Hint: Fix column with $ to check same column across rows [OK]

Common Mistakes:

• Using absolute reference for both row and column
• Not fixing column, so formula shifts incorrectly
• Removing quotes around text in formula

5. You want to highlight cells in range A1:A10 that are either empty or contain a number less than 5. Which custom formula will work correctly?

hard

A. =AND(ISBLANK(A1), A1<5)

B. =OR(ISBLANK($A$1), $A$1<5)

C. =OR(ISBLANK(A1), A1<5)

D. =OR(ISBLANK(A$1), A$1<5)

Solution

1. Step 1: Understand the condition logic

   We want to highlight if cell is empty OR if its value is less than 5.

2. Step 2: Check formula correctness and references

   =OR(ISBLANK(A1), A1<5) uses OR with ISBLANK and A1<5, with relative reference A1, so it applies correctly to each cell in A1:A10.

3. Final Answer:

   =OR(ISBLANK(A1), A1<5) -> Option C

4. Quick Check:

   Use OR and relative reference for correct rule [OK]

Hint: Use OR for either condition and relative cell reference [OK]

Common Mistakes:

• Using AND instead of OR
• Fixing cell reference so formula doesn't adjust
• Using wrong row or column references