Marathon Pace Calculator
Whether you're preparing for your very first half marathon or you've been running for the last twenty years, this marathon pace calculator will surely help you plan your race. It is a variation of our pace calculator that is designed specifically for runners. You can use it to figure out how fast your half marathon pace needs to be in order to get to the finish line in 2 hours or what your speed was during the last event you participated in.
In this article, you will also learn:
 How to use this marathon calculator; and
 The difference between pace and speed.
Excited? Let's dive right in!
What is the difference between pace and speed?
You can use this marathon calculator to establish three different values: the time it will take to run a certain distance, your average speed, or pace (see speed calculator). While the term time is selfexplanatory, the other two might require clarification.
The average speed tells you how many kilometers or miles you run (on average) during one hour. You can calculate it easily by dividing the race's total distance by the time you took to run that distance.
On the other hand, the average pace describes how much time you need to run one kilometer or mile. We usually express it in minutes per unit distance; for example, your average marathon pace can be equal to 7:21 minutes per kilometer.
How to use our marathon pace calculator – calculate your marathon pace
The first application of this marathon calculator is planning your race in advance – that is, establishing what pace you require to finish in a given time. To find it out, simply follow the steps below:

Choose the type of race you will participate in. It can be a marathon, half marathon, or even a 10kilometer race. Let's assume that you plan to do a full marathon.

The marathon pace calculator will automatically fill in the field "distance," showing you the distance you'll have to run. In the case of a marathon, it is 42.195 km. Feel free to change the units to miles if you prefer the imperial system.

Decide on your goal. For example, you might want to run a full marathon in under four hours, so you set your goal to 4h. Input this value into the "time" field.

Our marathon time calculator will automatically display the speed you need to achieve such a result – 10.55 km/h.

The next value, your required pace, is what probably interests you the most. To make a marathon in under 4 hours, you need an average pace of 5.69 min per km (5 minutes and 41 seconds).
How to use our marathon pace calculator – calculate your marathon time
You can also use this marathon pace calculator to predict the time of your race based on your average training pace. To do it, you need to follow a very similar method as above.

First, choose the type of event. Let's say that you're preparing for a half marathon this time.

The marathon time calculator will automatically display the distance – in this case, 21.098 km.

Instead of choosing your goal, leave the "time" field blank for now and input your average pace. Let's assume that the last time you trained, you were able to reach 4:30 minutes per kilometer.

You will immediately obtain the average speed that you achieved – 13.33 km/h. That's pretty impressive!

Now, take a look at the "time" field. Our marathon calculator will give you your estimated running time. In this case, running a half marathon should take you about 1 hour and 35 minutes.
Further reading
If you tend to exercise a lot, take a look at the target heart rate calculator. It will help you plan out your workouts and avoid situations that are dangerous for your health.
FAQ
How do I calculate marathon pace?
To know how fast you need to run to complete a marathon in a given amount of time, let's say 3 hours, perform the following calculations:

Convert time to minutes:
3 × 60 = 180

Divide the time (in minutes) by the distance (in kilometers):
180/42.195 = 4.2659

We got the pace of
4.2659 min per km
. 
We can rewrite our result as
4 min 15 sec per km
.
What pace is a 4 hour marathon?
The pace required to complete a marathon in 4 hours is around 5 min 40 sec per km, that is 9 min per mile.
What pace for a 2 hour marathon?
You would need to keep the pace of 2 min 50 sec per km, that is 4 min 34 sec per mile, to complete a marathon in precisely 2 hours. You'd beat the world record, wow!
What is a good marathon pace?
The very elite runners can complete a marathon in slightly more than 2 hours, while the top 5% in under three hours. The following table shows you the distribution of marathon times.
Marathon time  Men  Women 

Less than 3 h  4%  1% 
3 to 4 h  39%  20% 
4 to 5 h  38%  44% 
5 to 6 h  16%  26% 