Half marathon mileage: how many miles a week you need
Half marathon mileage for a first finish is modest: three or four runs a week with a long run that builds to 10 to 12 miles, and a weekly total that grows gradually from wherever you are now. This page explains how much is enough, how the total should grow, and what changes when you chase a time. The generator below builds the numbers from your current weekly mileage and longest run.
Weekly mileage for a half marathon by goal
There is no single right number, but there is a right shape: enough weekly volume that the long run is a part of the week rather than the whole of it. A useful rule: the long run should not be much more than half of the weekly total. A 12-mile long run wants a week of 20 miles or more around it.
| Goal | Runs per week | Long run peaks at | The rest of the week |
|---|---|---|---|
| Finish a first half | 3 to 4 | 10 to 12 miles | Easy runs only |
| Finish a second one faster | 4 to 5 | 10 to 12 miles | Easy runs plus one tempo session |
| Chase a specific time | 5 to 6 | 12 to 14 miles | Easy runs, one tempo, strides |
The generator uses the same logic: it starts your weekly total from the current mileage you enter, or from 3.5 miles per run day if you leave it blank, and caps the long run at 14 miles for the half. The beginner plan is the first row of the table; the intermediate plan is the second.
Build your free half marathon plan
Same engine as every plan on this site, but with your race date, your run days and your longest recent run. Prints to PDF, exports to your calendar. No signup.
How the weekly total should grow
Gradually, with a step back every few weeks. The plan engine aims a first half at a 25-mile peak week, about 31 if you have raced the distance before, and solves the weekly growth so your starting volume reaches that peak by the last week before the taper, between 3 and 15 percent a week. The long run grows the same way toward its 14-mile cap. Every fourth week is a cutback at 82 percent of the week before; the taper never contains a cutback. Those are the rules behind every table on the plan pages.
One limit worth knowing: the sample tables start from the minimum volume, 3.5 miles per run day, because no current mileage was entered. If you already run 20 miles a week, the sample 12-week plan starts too low for you. Enter your real weekly mileage and longest run in the generator and the early weeks move up while the peak stays the same, so the ramp gets gentler. The engine does not adjust for missed weeks either; if you lose two weeks to illness, regenerate from where you are.
Base mileage for a half marathon before the plan starts
A 12-week plan assumes you can run two or three times a week and cover 3 to 4 miles at a time. If that is not true yet, the fix is a longer plan, not a harder start. The couch to half marathon plan takes 16 weeks and begins with short runs. The Comeback preset in the generator slows the growth for anyone returning from a break. Building base is boring and it is the part that keeps you healthy in the build phase.
Good weekly mileage for a half marathon time goal
More runs, not longer runs. Adding a fourth or fifth easy day raises the weekly total with less strain than stretching the long run past 12 miles. It also gives the tempo session somewhere to sit. The plan puts the hard day mid-week, never on the long-run day, and only when you run four or more days. Most of the volume stays at easy pace, which the engine sets as race pace plus a fixed offset. Pick the target on the half marathon pace chart, for example 1:45, and the plan prints the easy, long and tempo paces that go with it.
Frequently asked questions
What should my weekly mileage be for a half marathon?
Enough that a 10 to 12 mile long run is no more than about half of the week, spread over three to five runs. The generator builds the exact totals from your current mileage.
What is the minimum weekly mileage for a half marathon?
Three runs a week with a long run that reaches 10 miles is the floor for running the whole distance. Less than that and plan on walk breaks.
What is the average weekly mileage for a half marathon?
There is no reliable average to quote, and this site does not invent one. The useful question is how much your own week needs to grow for the long run to reach 10 to 12 miles safely.
How much weekly mileage for a half marathon if I only run three days?
Three days works for a finish: two easy runs and a long run, with the weekly total growing by a little each week. Add a fourth day before you add a tempo session.