What pace is a 4-hour marathon?

9:09 per mile, or 5:41 per kilometre, held for the full 26.2 miles. Halfway should come through at 2:00:00, ideally a touch slower rather than faster.

What pace do I need for a sub-3-hour marathon?

6:52 per mile or 4:16 per kilometre. That requires a 10 km time around 38-39 minutes and a half marathon under 1:25 as supporting evidence of fitness.

Should I run even splits or negative splits?

Aim for even or very slightly negative. The vast majority of marathon personal bests come from a second half that is equal to or faster than the first, and almost every disaster comes from the reverse.

How much does heat slow marathon pace?

Meaningfully. Above roughly 15C, expect to lose time progressively - commonly 2-5% by 20C and more beyond that. Adjust the goal on the morning rather than defending a pace the conditions no longer support.

Why does my watch say I ran further than 26.2 miles?

Courses are measured along the shortest legal route. Weaving through crowds, taking wide corners and GPS drift typically add 0.2-0.5 miles, which means your watch pace looks faster than your official pace.

Marathon Pace Calculator

Find the exact pace per mile and per kilometre needed to hit your marathon goal time, with split times along the way.

Enter your details and your result will appear here.

What Is Marathon Pace?

This marathon pace calculator converts a goal finish time into the pace you must hold across 26.2 miles, along with the split times to check against on the day.

The marathon punishes pacing errors more than any other common distance. Thirty seconds a mile too fast through halfway does not cost you thirty seconds a mile at the end - it costs several minutes, and often the goal entirely.

Understanding Your Marathon Pace Result

The marathon is 42.195 km, or 26.219 miles. Divide your goal time by that distance and you have the required pace.

The numbers themselves are memorable landmarks. A sub-4:00 marathon needs 9:09 per mile. Sub-3:30 needs 8:00. Sub-3:00 needs 6:52. Each of those is a pace many runners can hold for ten miles - the marathon is the question of whether you can hold it for twenty-six.

Even pacing is the standard advice because glycogen depletion is unforgiving. Running the first half faster than goal pace burns carbohydrate at a disproportionate rate, and the second half is where that bill arrives, generally somewhere around mile twenty.

How Is Marathon Pace Calculated?

Required pace = goal time / 26.2 miles (42.195 km)

How to use this marathon pace calculator

Enter your goal finish time and the calculator returns the required pace per mile and per kilometre, plus split times at the key checkpoints.

Write the splits on your hand or a pace band. Doing division at mile eighteen is not a plan.

Setting a realistic goal time

Your recent half marathon is the best predictor: double it and add 10-20 minutes for a well-trained runner, more if your long runs have been short. A 10 km time multiplied by roughly 4.7 gives a similar estimate.

Goals built on a good training week rather than a race result are usually 10-15 minutes optimistic, and the marathon collects that debt in the last six miles.

Executing on race day

Run the first three miles deliberately slower than goal pace and let the crowd go. Take carbohydrate from around 45 minutes onward, roughly 30-60 g per hour, before you feel you need it.

Adjust for conditions in the first mile, not at mile twenty. A goal set in January does not survive an unexpectedly warm April, and the runners who accept that early are the ones still running at the end.

Methodology

Required pace is goal time divided by the official marathon distance of 42.195 km, converted between units with the exact 1.609344 factor. Splits are projected at even effort, which is the pacing strategy most closely associated with successful marathon performances.

Worked Example

A 4:00:00 marathon requires 9:09 per mile or 5:41 per kilometre. Halfway comes at 2:00:00, and 20 miles at 3:03.

A 3:30:00 marathon requires 8:00 per mile, with halfway at 1:45:00. To finish under either target you want the first half a minute or so slower than the even split, not faster - which contradicts how good you will feel at mile three.

Important Limitations

Required pace is arithmetic, not a prediction of what you can sustain. Heat, hills, wind and course crowding all raise the effort at a given pace, with warm conditions costing several minutes over the distance. GPS distance error means watch pace and official splits will disagree, and most runners record slightly more than 26.2 miles because they do not run the racing line. Fuelling and hydration determine whether goal pace survives past mile twenty, and no calculator can account for those.

Frequently Asked Questions

What pace is a 4-hour marathon?: 9:09 per mile, or 5:41 per kilometre, held for the full 26.2 miles. Halfway should come through at 2:00:00, ideally a touch slower rather than faster.
What pace do I need for a sub-3-hour marathon?: 6:52 per mile or 4:16 per kilometre. That requires a 10 km time around 38-39 minutes and a half marathon under 1:25 as supporting evidence of fitness.
Should I run even splits or negative splits?: Aim for even or very slightly negative. The vast majority of marathon personal bests come from a second half that is equal to or faster than the first, and almost every disaster comes from the reverse.
How much does heat slow marathon pace?: Meaningfully. Above roughly 15C, expect to lose time progressively - commonly 2-5% by 20C and more beyond that. Adjust the goal on the morning rather than defending a pace the conditions no longer support.
Why does my watch say I ran further than 26.2 miles?: Courses are measured along the shortest legal route. Weaving through crowds, taking wide corners and GPS drift typically add 0.2-0.5 miles, which means your watch pace looks faster than your official pace.