How Long Does It Take to Train for a Half Marathon? (It Depends Where You Start, So Start There)

Most answers to this question start with a number and only mention later who it applies to. That order is backwards. Twelve weeks is the standard answer, but it assumes you can already run for about half an hour, several times a week. A lot of people asking the question can't do that yet, and nobody tells them until week two of a plan goes badly.

So this post starts with where you are now. Find your starting point below, count forward, and you will know whether your race date works.

How long does it take to train for a half marathon?

For most beginners it takes 12 to 16 weeks, as long as you can already run about 5K comfortably. Starting from no running at all, plan on roughly six months. That covers building up to 5K first, settling into a routine, and then following a half marathon plan.

The race is 13.1 miles, or 21.1 kilometres. Fitness is not really what decides your timeline. What decides it is how many weeks it takes your legs to get used to steadily longer runs without anything breaking down. That process has a minimum length, and willpower does not shorten it.

How long does half marathon training take if you can already run 5K?

Plan on 12 weeks, plus a few spare weeks if you can fit them in. Twelve weeks is the length of one of the most widely used beginner plans, Hal Higdon's Novice 1 half marathon program. It has a clear entry requirement. On his site, Higdon says the schedule assumes you can already run 3 miles, three to four times a week. If that seems difficult, he suggests choosing a shorter race first.

Over those 12 weeks the long run builds from 3 miles to 10. You never run the full 13.1 in training. Race day covers the last stretch. Most beginner plans work like this, and it surprises people. You don't need to have run the distance before the race. You need to have built up to most of it.

Leave a little slack. Twelve weeks only works if nothing goes wrong, and something usually does. A cold, a work deadline or a week of awful weather can eat a week. Sixteen weeks gives you room to repeat a week without panicking. If you just finished a beginner programme, what to do after Couch to 5K covers the gap between finishing and being ready for a plan like this.

How long does it take to train for a half marathon from zero?

About six months, sometimes a bit longer. The time breaks into three stages, and each one is real.

Getting to 5K: about 9 weeks, often more. The NHS Couch to 5K plan takes complete beginners to 30 minutes of continuous running in 9 weeks, with three runs a week. The NHS says plainly that you can repeat any week until you feel ready to move on, and many people do. It also notes that for slower runners, 30 minutes of running may come to less than 5K. That's normal. It just means one more week of patience. How long it takes to train for a 5K from scratch breaks this first stage down week by week.

Settling in: about 4 to 6 weeks. Finishing a 5K plan does not mean you are ready for a half marathon plan the next day. Higdon's plan expects three or four runs a week of around 3 miles from the very first week. Most people coming out of Couch to 5K have been running three times a week for 30 minutes, and some of those runs still feel hard. Spend a month making those runs feel ordinary. Some runners add a fourth short run during this stage. How many days a week a beginner should run goes through when that makes sense and when it doesn't.

The half marathon plan itself: 12 to 16 weeks. Add it up and you get roughly 25 to 31 weeks. Six months is the honest answer. Anyone promising a faster route from the sofa to 13.1 miles is either assuming a lot about your body or not thinking about you specifically.

How long does it take if you used to run and are coming back?

It depends less on what you used to do and more on what you can do this week. Go out and run easily for 30 minutes. If that goes fine, treat yourself as a 5K-ready runner and plan 12 to 16 weeks. If it doesn't, start from the 5K stage. Previous experience usually means that stage goes faster, but don't skip it.

Returning runners tend to remember their old long runs and their old paces, and they start from there. Your memory is not your current fitness. Begin from what you can do now, and the comeback will probably move faster than you expected.

Is my race date realistic?

Count the weeks from today to race day, then compare that number with your starting point above. If you can run 5K and the race is at least 12 weeks away, it is realistic. If you are starting from zero and the race is at least 26 weeks away, it is realistic. If you have fewer weeks than that, the date is tight, and tight is when beginners get hurt or give up.

Many first half marathons are spring races. From mid-October, a race in mid-April is about 26 weeks away. That is just enough for someone starting from zero, provided nothing goes wrong. A March race is fine for someone who can already run 5K. It is too soon for someone who can't yet.

If the numbers don't work, the options aren't bad. Choose a later race, or run a 10K on the original date and do the half marathon in the autumn. Arriving at the start line ready matters more than racing on a particular date.

Should I sign up for a half marathon now or wait?

Sign up now if your timeline fits with a few spare weeks. Wait if it only fits when everything goes perfectly. Having a date on the calendar does help people keep going, because it gives every training week a purpose. Committing to a date your body can't realistically meet does the opposite. You fall behind, the plan stops working, and the entry fee starts to feel like a penalty.

A good middle option is to start training first. Give yourself four weeks. If the runs are getting done and nothing hurts more than normal tiredness, enter the race then. Popular races fill up, so look at the entry deadline, but most beginner-friendly half marathons don't sell out months ahead.

What should I do if I'm not ready to start a half marathon plan yet?

Start the stage below it. If you can't run 5K yet, start a 5K plan this week. If you can run 5K but it still feels hard, run three easy sessions a week for a month and make them slow enough that you could talk while running.

Going slow is how you get there. Most new runners who can't go further are running too fast to go further. How to run longer without getting tired explains why slowing down comes first and adding distance comes second.

Use this time to build a routine, and fitness will come with it. The runners who reach the half marathon start line are rarely the ones who had the hardest weeks. They are the ones who kept turning up week after week.

Why do beginners need extra weeks built in?

Missed weeks are expected, not a sign you've failed. Over four to six months, almost everyone loses some time to illness, travel, work or a sore spot that needs a few easy days. A plan with no spare weeks makes every one of those feel like an emergency. A plan with spare weeks lets you repeat a week and carry on.

If pain lasts beyond normal post-run soreness, or changes the way you run, see a doctor or physiotherapist. Don't try to train through it. This post can tell you how long training takes. It cannot tell you why something hurts.

Joggy, the turtle in our app, was built for exactly this kind of slow, steady build. Its AI training plans start wherever you actually are, including zero, and streaks track whether you're showing up rather than how fast you are. If you'd like the weeks laid out for you, Joggy is on the App Store and Google Play. If you'd rather use a free printed plan, the counting above works just as well.

Sources

• Hal Higdon, Novice 1 Half Marathon Training Program
• NHS Better Health, Couch to 5K running plan
• NHS Better Health, Get running with Couch to 5K