Quick Answer
LOG10 Function
Returns the base-10 logarithm of a number.
✓ Excel✓ Google SheetsExcel All versions
Syntax
LOG10
(number)
Parameters
| Parameter | Description | Required |
|---|---|---|
| number | The positive real number for which you want the base-10 logarithm. | Required |
Basic Example
Base-10 log of 1000
=LOG10(1000)Result3
10³ = 1000, so the base-10 logarithm is 3.
Advanced Examples
Example 1: Log of 1
Baseline check.Any base log of 1 is 0.
=LOG10(1)Result: 0
10⁰ = 1, so the result is 0.
Example 2: Log of 2
Order-of-magnitude estimate.Irrational result.
=LOG10(2)Result: 0.301029996
10^0.30103 ≈ 2.
How LOG10 Works
LOG10 computes log₁₀(number), the power to which 10 must be raised to equal the input. It is equivalent to LOG(number, 10) and to LN(number)/LN(10).
1
Select the cell
Click the cell for the result.
2
Enter the formula
Type =LOG10(number).
3
Press Enter
The base-10 logarithm appears.
Important Notes & Limitations
The argument must be strictly positive; zero or negative returns #NUM!.
Results are floating-point approximations.
For other bases use LOG(number, base).
Common Errors & Fixes
#NUM!Argument is 0 or negative.Fix: Pass a positive number.
#VALUE!Non-numeric argument.Fix: Supply a numeric value.
Download Practice File
LOG10
log10Practice LOG10 with Real Data
Download a sample CSV file with pre-populated data and practice exercises for the LOG10 function. Works in both Excel and Google Sheets.
Works in Google SheetsCompatible with ExcelIncludes exercises
File format: CSV (comma-separated values) - opens in Excel, Google Sheets, and all spreadsheet apps
Frequently Asked Questions
Is LOG10 the same as LOG(...,10)?
Yes. LOG10(number) equals LOG(number, 10); LOG10 is just a convenience function.
Why does LOG10(1) = 0?
Any base logarithm of 1 is 0 because the base raised to 0 is 1.
How do I get a natural log instead?
Use LN for base e, or LOG(number, base) for an arbitrary base.