# ISNUMBER

The **ISNUMBER** function returns TRUE if the specified cell value is a valid numeric value. It returns FALSE if the value is not a number. It is commonly used with IF and other conditional functions to validate numeric inputs before performing calculations.

### Syntax

```javascript
ISNUMBER(value)
```

### Arguments

value - The value to evaluate. Required.

### **Return value**

Either TRUE or FALSE.

### **Example**

<pre class="language-javascript"><code class="lang-javascript"><strong>IF(ISNUMBER([2027 Plan]),[2027 Plan]*1.05,"Not a number")
</strong></code></pre>

In this example, the **ISNUMBER** formula checks whether the *2027 Plan* contains a numeric value and returns TRUE or FALSE accordingly. If TRUE, the IF function calculates a 5% increase in the plan value. If FALSE, it returns "Not a number".

<figure><img src="/files/UVUgQz6Xv3EEJ4HWo3EI" alt=""><figcaption><p>Applying ISNUMBER function</p></figcaption></figure>

### **Excel equivalent**

[ISNUMBER](https://support.microsoft.com/en-us/office/is-functions-0f2d7971-6019-40a0-a171-f2d869135665)


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