When counting the number of times for objects appear in a list or a range, we usually record the duplicate value only once and ignore the redundant ones. We cannot apply formula with only one function to implement this in excel, so we need to update formula and use a formula combine more than one functions. This free tutorial will introduce you to **count objects only once by the combination of SUMPRODUCT and COUNTIF functions**.

**Precondition:**

Insert a list with some products. You can see there are some duplicate values. We will introduce you the method to count numbers ignore the redundant duplicate values. Actually, for case-sensitive and case-insensitive two different situations, we provide two ways with two different formulas to count numbers.

Table of Contents

**Part 1: Count Duplicate Values Once with Case Sensitive**

**Step 1:** Select a blank cell just next to the list, for example B2, enter the formula **=SUM(IFERROR(1/IF(A2:A11<>””, FREQUENCY(IF(EXACT(A2:A11, TRANSPOSE(A2:A11)), MATCH(ROW(A2:A11), ROW(A2:A11)), “”), MATCH(ROW(A2:A11), ROW(A2:A11))), 0), 0))**.

**Step 2:** Press **Shift+Ctrl+Enter** on keyboard simultaneously to get result.

As we count number with case sensitive in this sample, so product ‘NPS001’ and ‘nps001’ are processed as two different products.

**Part 2: Count Duplicate Values Once with Case Insensitive**

This time we count number with case insensitive.

**Step 1:** In B2 enter the formula **=SUMPRODUCT((A2:A11<>””)/COUNTIF(A2:A11,A2:A11&””))**.

**Step 2:** Press **Enter **directly to get result. Verify that this time the count number is 5, so this time products ‘NPS001’ and ‘nps001’ are considered as duplicate values.

### Related Functions

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