Learn how to use the ln function in Notion formulas.
For reference, here are the named components of a logarithm:
A logarithm is the exponent of the base that returns the argument.
Learn more about the natural logarithm:
In plain English,
helps us find out how many periods (i.e. how long) of continuous growth are needed for a starting value to reach a target end value.
denotes a continuous rate of growth.
is our starting population, and
is the number of periods.
At the end of three years, our final population is 20,085.
Now let’s look at
tells us how much growth we’ll experience given a number of periods,
tells us how many periods it’ll take to get a specific end result
We can now see that
is the inverse of
. Therefore, these two are roughly equivalent (20,085 is rounded from the actual result of the first equation):
This also means:
Hopefully this aside has helped to demystify
a bit for you!
ln(20) // Output: 2.995732273554
ln(e) // Output: 1
This example database calculates the calculates the number of years needed for a starting population to reach a target end number given a specific growth rate.
round(ln(prop("Target Num") / prop("Starting Num")) / prop("Growth Rate") * 100) / 100
prop("Target Num") /
) / 100
The first part of this formula replicates the mathematical example in the toggle block above.
First, we find the natural logarithm of the quotient of the Target Num and the Starting Num:
This is done with the following code:
ln(prop("Target Num") / prop("Starting Num"))
Next, we divide this result by the Growth Rate.
My name is Thomas Frank, and I'm a Notion-certified writer, YouTuber, and template creator. I've been using Notion since 2018 to organize my personal life and to run my business and YouTube channel. In addition to this formula reference, I've created a free Notion course for beginners and several productivity-focused Notion templates. If you'd like to connect, follow me on Twitter.