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**LOG10(**//expression//**)**

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| **LOG10** | Returns base 10 logarithm. |
| //expression// | A numeric constant, variable, or expression. If the value of the //expression// is zero or less, the return value will be zero. The base 10 logarithm is undefined for values less than or equal to zero. |

The **LOG10** (pronounced "log ten") procedure returns the base 10 logarithm of a numeric //expression//. The base 10 logarithm of a value is the power to which 10 must be raised to equal that value.

| **Return Data Type:** | REAL |

**Example:**

**  !LOG10(10)   returns 1**

**  !LOG10(1)    returns 0**

**LogStore = LOG10(Var)          !Store the log 10 of var**

**See Also:**

[[loge  return natural logarithm .htm|LOGE]]