Learn how to use the log10 function in Notion formulas.
The log10() function returns the base-10 logarithm of a number.
1
log10(number)
For reference, here are the named components of a logarithm:
logbaseargument=exponent
A logarithm is the exponent of the base that returns the argument.
Example Formulas
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log10(1000)// Output: 3
2
3
log10(10)// Output: 1
Want to learn more about logarithms? Check out this resource:
Using Logarithms in the Real World – BetterExplained
Computing Logs with Other Bases (Log Base X)
Notion only provides log10(), log2, and ln because those are by far the most commonly-used log bases.
However, if you need to compute a log with a different base, you can use the change of base formula:
logxy=(lnxlny)
So, for example:
log381=(ln3ln81)
Here’s a Notion formula to compute this:
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ln(81)/ln(3)// Output: 4
Example Database
log10
can be used to perform an interesting mathematical trick – finding the length (i.e. number of digits) in any number. It is done by taking the floor value of a number’s
log10
, then adding one:
⌊log10n⌋+1
The example database below shows this trick in action.
View and Duplicate Database
log10
College Info Geek on Notion
"Length" Property Formula
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// Compressed
2
floor(log10(prop("Num")))+1
3
4
// Expanded
5
floor(
6
log10(
7
prop("Num")
8
)
9
)+1
If you’re curious about the math behind why this trick works, check out this thread:
Proof: How many digits does a number have? $\lfloor \log_{10} n \rfloor +1$
Mathematics Stack Exchange
The formula itself is quite simple:
1.
We pass prop("Num") to the log10() function.
2.
This value is then run through the floor function in order to round it to its nearest integer of lower or equal value.