Murphy’s (Sod’s) Law Calculator

This is the Murphy’s Law Formula (also known as Sod’s Law Formula). All the values you enter should be between 0 and 1. Think of it as a 1 to 10 scale except with a decimal in front of it. Pay attention to this otherwise you will get a weird or wrong answer. Use this to determine the chances that something will go wrong. The example answer below .1575 means there is a 15% chance of something going wrong.

For Example: If the task has an urgency of 5 on a scale of 1 to 10. Put a decimal in front of it and use .5 as the answer.


If the calculator above doesn’t work you can go to the page I built it on for the javascript version.

I built this calculator based on several sources of Murphy’s Law. If you want to read more about this you can look here, here, here and here. If you want a list of contextual laws and more go to Murphy’s Laws for more laws than you can shake a stick at.