How You Can Predict Your Marathon or Half-Marathon Finish Time?

Use these methods to find your race pace

Finish Line
By U.S. Navy photo by Candice Villarreal/Wikimedia Commons/Public Domain

When you register for a half-marathon or marathon, you are likely to be asked what your likely finish time and pace will be. If you haven't finished one of these races before, you probably wonder how to estimate these numbers. If they don't ask for this prediction, it is still important for you to know your likely finish time so you know you are able to make the finish time cutoff. Here are ways to get calculate these answers.

How to Predict Your Finish Time for a Marathon or Half-Marathon

There are charts and calculators to determine what your half-marathon and marathon time might be based on your current race speed. It is best to use an actual time for a hosted event, as that is when you are performing at your peak. You might schedule a 5K or 10K race before you register to see your pace at those distances.

While experienced runners often know their race pace, walking coach Judy Heller notes that it is much more difficult for walkers and those who use the walk/run method to know their pace. Here are three ways to make the prediction:

  • Runner's World Race Prediction Calculator: Enter your actual times for various distances to predict your time for any other distance.
  • Marathon coach Hal Higdon suggests finding your marathon finish time by multiplying your 10 kilometer time by 5, if you are a first-timer, or 4.66 if you are an experienced marathoner.
  • Dr. John Robinson suggests this method: Add 20 seconds to your mile each time you double your distance. If you have done a half marathon, take your average minutes per mile, add 20 seconds and multiply by 26.2.

Enter an Accurate Finish Time Prediction When You Register for a Race

The race organizers need to know your predicted finish time. At larger races, you will be assigned to a corral based on finish time. They release the corrals a minute or two apart to keep the course from being congested. By placing racers of the same speed together, they can reduce problems of people blocking faster racers during the first few miles of the race. Don't try to sneak into a faster corral—it's unpleasant and dangerous to be stampeded for those early miles. Not only will you annoy faster racers, you will find it unpleasant.

Don't Enter an Event You Can't Finish by the Cutoff Time

Do not enter an event if you might not make the cutoff time. There are many half marathons and marathons available that are walker-friendly with no cutoff time or a generous cutoff time of eight hours or even longer for a marathon. Choose one of those events for your first marathon. It's different at the tail end of a race, and even worse if you are slower than the cutoff time allows. You'll often find the water stations being folded up, route markings being removed, and the course being opened to traffic.

Late Finishers Endanger Marathons

Event directors hate people who enter their events even though they can't make the cutoff. Races often have expensive permits and contracts to close streets to make a safe course for the participants. They must reopen the streets by the stated times, which on some courses makes it unsafe or impossible for the walkers or runners to continue on the course. They also have water stops and aid stations set up with those same expectations. Their volunteers may close up shop and depart, leaving you without any support.

If You're Lagging, Take the Sag Wagon

The most enraging issue for event directors are walkers and runners who are lagging behind but refuse to get into the "sag wagon" to safely transport them to the finish. They can't kidnap you from the course against your will. But you are a lawsuit waiting to happen if you are injured on the course once they have reopened it to traffic and no longer have water stops and other support services.

The result often is the event director making the finish time even more restrictive to dissuade walkers and run/walkers from registering. If your expected finish is near the cutoff time, make a firm pledge that you will take the sag wagon if you are not on the proper finish pace. Otherwise, you are part of the problem.

You'll have to take a DNF (did not finish) but you can make that into a win. Use the experience to focus on fully training for your next race.