# Calculating difference between Planned Effort and Actual Effort?

Here’s the scenario we’re trying to make work with columns:

Planned Effort column - Manually enter the ESTIMATED time to complete the task
Time Tracking column - Enter your ACTUAL time spent working on the task
Planned vs. Actual Effort column - Displays the difference between Planned and Actual (positive or negative)

So in practical terms:

I estimate that a task will take 15 hours. After tracking my time and completing the task, I see that it only took me 7 hours. I can see on the Planned vs. Actual Effort column that I am 8 hours UNDER the Planned Effort. Or maybe it took me 27 hours, and I can see that I am 12 hours OVER the Planned Effort.

We want to do this because we suck at estimating how much time a task will take. We sure could use the over/under numbers to get better at estimating task time in the future.

Can we take the total time from the Time Tracking column, subtract it from the Planned Effort column, and display the result (positive or negative) in a third column, with a sum at the bottom?

Here’s a rough mockup of what I’m talking about. I hid a lot of columns to make it easier to see:

If there’s a better way to do this, I’m all for it!

[Edited because my numbers didn’t add up in the original screenshot]