Posted on 3 Comments

Race Prediction: how fast should you run?

Predict how fast to run a race
AOYS Race Prediction, how fast should I run, how fast to run, how to predict race time

Race Prediction – how fast should you run?

We’ve done it, we’re committed. We’ve signed up for a race. Handed over cash, told friends and family. Asked for sponsorship. It’s definitely happening! The question you’ll be asked most often, (by others, and you will ask yourself too), is: “what time do you want to get?”

Most of us have an inkling, and even if you really do just want to ‘get round’, it is a really good idea to have an idea about what time you want to ‘get round’ in. Whatever time you want to finish in, by knowing what that is, you can work out your pace so you can run or run/walk your way round a course with an even pace.

Running at the same pace the whole way is the best way to hit a time without blowing up and slowing down unintentionally.  Going too fast at the start is a classic mistake.  I relax and smile when I stick to my planned pace while others surge past me at the start, knowing I will pass them later as they’re walking at mile 18.  A good rule of thumb is that for every minute too fast that you run the first half of a marathon, you’ll lose two minutes in the second half!

The best way to get a prediction and find your pace, is to do another event, and use online tools to work out your prediction for your chosen event.

How to make your prediction as accurate as possible

There are a couple of important ways to make your prediction as accurate as you can:

Use a distance as close to your target race distance as possible

So, to predict a marathon, a half marathon time will give you a more accurate prediction than a 5k time.

Use a recent result

Your school 800m time wont give you an accurate readout, unless maybe you’re at exactly the same fitness now. The tools work based on your current fitness.

Think about your experience

New runners often find that they can perform well in one race distance pretty quickly but may take a few goes running a different distance before they really learn how to run it. This is very common for your first marathon. In this case it’s best to be conservative, enjoy it, and you’ll always get a Personal Best for your first one anyway. Hopefully you’ll have a good experience with your brilliant pacing and come back for more!

Keep training!

A prediction isn’t a golden ticket to that PB you’ve always wanted. It presumes you continue to be fit and carry on training. You can’t just plug in a time, admire the prediction and put your feet up! So keep going, with the added motivation of that predicted time you could get!


So how fast can I go?

The million dollar question! Below is a table of quite conservative estimates of marathon times from half marathon times.

Marathon prediction chart, predict marathon times, how fast can I run marathon

For more accurate predictions based on what you’ve already run, check out some online calculators.  The Fetch marathon predictor works off half marathon time and the Fetch race predictor calculates any distance off any other distance race time. These are based off evidence of real runners’ performances over a range of times, rather than pure stats or elite performances only, and both link to other calculators if you’d like to investigate further.

A final word of caution. Not everyone will fit these perfectly. I personally don’t think I fit the calculators, and tend to run better over longer distances than my shorter distance results predict. So use them as a guide but don’t feel limited by them.

So good luck, enjoy it and I hope you run a PB / PR! Let me know how you get on and ask any questions in the comments below.

Related links

For Pacing tips & pacing products, see Pacing

For more tips on marathon prep, see Get Marathon Ready

To support runners taking on a race, see Good Luck cards & gifts

To congratulate runners finishing a race, see Race Finisher cards & gifts

You can get pace band temporary tattoos or pace pockets here:

  • Pace band for half marathon in kms
    Pace Transfers – Half Marathon – KMs
  • Pace band for half marathon in miles
    Pace Transfers – Half Marathon – Miles
  • Pace band for marathon in kms
    Pace Transfers – Marathon – KMs
  • Pace band for marathon in miles
    Pace Transfers – Marathon – Miles
  •  pace pocket 4H00 KM
    Pace Pockets (KM)
  • Pace Pockets (Miles)
    Pace Pockets (Miles)

3 thoughts on “Race Prediction: how fast should you run?

  1. […] 2. Plan Plan your ideal marathon: What is your goal time and pace? Make sure you’ve tested your marathon pace in some runs, so you know what it feels like. [To work out how fast you should run, see here] […]

  2. […] to hold for longer in future. Racing also tests your fitness and progress towards your goal. (See here for how to predict how fast you can […]

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.