Running Calculator

This post is a bit different to what I usually put out there. In 2015 I got obsessed with running. Since then I have run almost 5000km. In 2019 I got badly injured and I haven’t been able to run since then. I’ve made a few tools to make my running training easier. I want to share them with you for free.

Base Building Calculator

I posted this tool on reddit in 2015, to this day I still get requests to view the spreadsheet weekly.

Base building is process where you slowly increase the total mileage that you are running each week. The idea is that you want to basebuild before you start a training program. For example if the training program calls for 100km a week and you can currently only run 60km a week, youll need to fill in the gap. Runners do this with base building. There are a few rules for base building:

  1. 10% rule – You should only increase your weekly mileage by about 10%
  2. Longruns/ LSDs – Your long run should be about 20 – 30% of your weekly mileage
  3. Midweek Long Runs – Midweek long runs, should you choose to do them, should only be 15 – 20% of your weekly distance
  4. Cut Back Weeks – Every 4th week you should have a rest week or cut back week. This is a reduction in your mileage of 10% from the previous week.
  5. Goal Mileage – your goal mileage for the base building period should be equal or slightly more than the recommended mileage of the training plan that you are getting ready for.

Ofcourse, this is a lot to think about which is why I made this free spreadsheet. All you need to do is enter the amount of days you run each week, and your goal mileage.

TIp: if you enter your goal mileage and the starting mileage is more than you currently run, it would be a good idea to add a few weeks onto the plan so you can get to the point where you can run the recommended starting mileage.

Download Running Mileage Spreadsheet Calculator

If the above download link doesn’t work you can send me an email at and Ill send you the spreadsheet.

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