5K
3.1 miles
A 5K plan that starts where you are.
Training plans for the 5K, 10K and half marathonbuilt from the miles you run now.
Answer six questions. Get a week-by-week calendar that starts where you are, builds in small steps, and schedules easier weeks along the way.
Free preview, no account. Your answers stay on your device. General training information, not medical advice.
14 weeks to a half marathon
20 to 26.5 miles a week. Sample plan from the engine.
Week 5 of 14Sample day
Next run
Easy run
4.9 mi
About 55 min10:35 to 11:55 /mi
- 5K, 10K and half marathon
- Miles and min/mi, built for US runners
- Same inputs, same plan
- Free preview, no account
Pick your race. We build the weeks.
Each distance has its own plan page showing what a build looks like, plus the tools that matter most for it.
10K
6.2 miles
A 10K plan with room to build.
Half marathon
13.1 miles
A half marathon plan that builds patiently.
See the whole plan before you run a mile
A real calendar, a real progression, a real workout. Select any run to read it. This sample is generated by our planning engine for a regular runner at 20 miles a week with a recent 10K, training 14 weeks for a half marathon, with regular runs capped at 60 minutes and the long run at 2 hours.
Your calendar Weeks 1 to 5
Week 1 · Nov 9 to 1520.0 mi
9Rest
11Rest
13Rest
Week 2 · Nov 16 to 2221.5 mi
16Rest
18Rest
20Rest
Week 3 · Nov 23 to 2923.1 mi
23Rest
25Rest
27Rest
Week 4 · Nov 30 to Dec 6 · easier18.3 mi
30Rest
2Rest
4Rest
Week 5 · Dec 7 to 1323.1 mi
7Rest
9Rest
11Rest
Easy Harder session Long run
Workout Sample day
Thursday, December 10
Tempo run
4.9 mi, about 55 min
- Effort
- Comfortably hard (about 6–7 out of 10): short phrases only
- Pace estimate
- 8:50 to 9:15 /mi
23 minutes easy, then 10 minutes steady and comfortably hard, then 22 minutes easy. If you can't hold the effort, slow down.
Week 5: 23.1 mi
Gradual build. A bit more mileage and one controlled harder session. Keep every other run easy.
Build a plan like thisWeekly miles Easier weeks are outlined
- 20
- 22
- 23
- 18
- 23
- 25
- 26
- 21
- 27
- 27
- 27
- 27
- 21
- 11
- Weeks 4 and 8Easier on purpose, so the next build lands well.
- Week 5Highlighted: a bit more mileage and one controlled tempo.
- Weeks 13 and 14Taper, then race week.
Sample plan, not a real runner's result. Engine version 0.3.1. Pace ranges are estimates from the 10K result and are not guarantees.
Free tools that use your numbers
Each works on its own with no sign-up, and several can hand your numbers to a full plan.
Race time predictor
Enter a recent race. See estimated times for other distances, with a plain note on how far estimates can be off.
Recent 5K 27:45Estimated 10K57:51
Estimated half2:07:39
Estimates assume similar training and conditions. Each row is labeled by how far it is from your race, which is our own rule of thumb.
Predict my timeTraining pace calculator
One recent result becomes pace ranges, not a single false-precision number.
Easy10:35 to 11:55 /mi
Tempo8:50 to 9:15 /mi
From a 10K in 55:00, four weeks ago.
Find my pacesPace calculator
Pace, distance and time in miles and kilometers, plus race-day splits.
5K in 27:45 = 8:56 /mi
Calculate paceRace readiness checker
Pick a race and the weeks you have. The planner tells you whether your mileage can build to it gradually, and what would make it fit.
Check my timelineExample: half marathon in 6 weeks, from 12 miles a week
In 6 weeks, a gradual build from 12 miles a week reaches about 14.5. A half marathon needs at least 20.
How it works
Three steps from a goal to a calendar. The rules are written down, applied the same way every time, and explained on How It Works.
- Step 1
Tell us where you are
Your goal, your weekly miles, the days and time you have. Six short questions.
- Step 2
We check the goal fits
If the timeline is too short for a gradual build, we say so and offer options that fit.
- Step 3
Follow your calendar
Every run says how hard it should feel. Add a recent race and paces come with it.
- Week 1 matches what you run now, not a template's starting point.
- Growth is capped: weekly miles rise in small steps and the long run by at most a mile a week.
- Easier weeks are scheduled, then a taper brings you to race day fresh.
- Runs land only on your days, within the time limits you set.
When a goal doesn't fit, we say so
Our planner will not squeeze a goal into a timeline that a gradual build cannot reach. When the timeline is too short, it explains why and shows what would work.
We can't recommend a plan from these answers
Building one anyway could push you too far, too fast.
- In 6 weeks, a gradual build from 12 miles a week reaches about 14.5. A half marathon needs at least 20.
- The long run only builds to about 6.5 miles, and a half marathon needs at least 8.
- A 10K fits your current timeline.
- More running days, or longer runs on your long-run day, would also help.
Real planner output for these answers, engine version 0.3.1.
Learn before you lace up
Guides, running science and a blog. Each article says what its claims are based on and when they were last checked.
Analysis
Goals our planner declines, and why
When the planner says no to a goal, it explains why and offers options. Four real examples, generated from the engine.
Blog post
How we check the planner before you see a plan
The tests behind every plan: unit tests, property-based safety checks, reviewed example runners, and what tests cannot tell us.
Blog post
Introducing Milewell: rule-based running plans
What Milewell is, what is free and what Premium adds, what does not exist yet, and how the rule-based planner works.
Guide
Easier weeks and the taper: why plans back off on purpose
Why our plans schedule an easier week every fourth build week and taper before race day, and what those weeks look like in a real plan.
Guide
Easy pace: how slow is easy?
What "easy" means in our plans, the pace the planner assumes with and without a recent race, and what to do when an easy pace feels hard.
Honest about what this is
Where an article shows numbers, they are generated from the same rules as the planner.
- Every article states its basis
- Claims come from our planner's published rules or from a cited source. We do not invent studies or experts.
- No credentials we don't have
- No coach or clinician reviews our content yet, and we say so. Health topics stay unpublished until a credentialed reviewer signs off.
- Read the details
- Our method and editorial policy.
Questions runners ask
More detail on How It Works.
Can I go from a few miles a week to a half marathon?
It depends on how many miles you run now, how many weeks you have and how long your runs can be. Our weeks-needed analysis shows where our planner says no, and the readiness checker answers it for your numbers.
Do I need a recent race?
No. Without one, every run comes with effort guidance. A recent race or time trial adds estimated pace ranges.
Is it free?
Yes, the core of it. The plan builder, the calculators, a free account with your saved plan, the training calendar and workout logging are free. Premium, which will add plan adjustments, is not on sale yet; see the pricing page.
Is this medical advice?
No. It is general training information. If you have pain, an injury or a health condition, talk to a doctor first.
Are there marathon plans?
Not yet. The 5K, 10K and half marathon come first so each can be done carefully.
Start with the miles you run now.
Six short questions. A week-by-week calendar at the end.
Build my plan