Running Mileage Progression Calculator

How the progression works

Week 1 is the number you enter. Each build week adds 10% to the last peak. Every fourth week is a cutback, set 10% below that peak. The next build week starts 10% above the old peak, not from the cutback. The athlete keeps what they gained, and the lighter week gives the body time to absorb the work.

Add a target peak to cap the build. Build weeks climb to that number, then hold there. Cutback weeks still fall every fourth week, at 10% below the target.

The Miles and Time toggle changes the unit, not the math. Minutes work well early in the season and on hilly or trail routes, where pace swings from day to day.

The daily split

The tool spreads each week across six running days. Sunday is a rest day.

• Monday: easy, 12%
• Tuesday: workout, 20%
• Wednesday: medium-long, 12.5%
• Thursday: maintenance, 12.5%
• Friday: easy, 12%
• Saturday: long run, 25%

Those shares add up to 94%, so the tool scales each one up to fill the week. In practice, the long run lands near 27% of the weekly total and the workout day near 21%.

A worked example

Here is the default plan: 30 miles to start, 12 weeks.

Week	Type	Weekly miles	Saturday long run
1	Build	30	8
2	Build	33	8.8
3	Build	36.3	9.7
4	Cutback	32.7	8.7
5	Build	39.9	10.6
6	Build	43.9	11.7
7	Build	48.3	12.8
8	Cutback	43.5	11.6
9	Build	53.1	14.1
10	Build	58.5	15.5
11	Build	64.3	17.1
12	Cutback	57.9	15.4

By week 11, the athlete is at 64 miles a week with a 17-mile long run. That is more than double where they started. The table compounds, so long plans climb fast.

So set a target peak before you start. On my year-by-year mileage table, most high school runners peak between 15 and 40 miles a week in summer base. Only experienced upperclassmen go past 40.

Here is the same plan with a target peak of 40 miles. Weeks 1 to 5 do not change. Week 6 rises to 40. From there, build weeks hold at 40 and cutback weeks drop to 36. The long run tops out near 10.6 miles.

Why step cycles, not the 10% rule

The old 10% rule says never raise weekly mileage by more than 10%. It is easy to remember. The research does not back it.

• In a 2008 Dutch trial, 532 new runners trained for a 4-mile race. One group followed a 13-week plan built on the 10% rule. The other followed a faster 8-week plan. Injury rates were nearly the same: 20.8% and 20.3%.
• In a 2025 study in the British Journal of Sports Medicine, 5,205 runners logged 588,071 sessions over 18 months. Week-to-week changes in total distance showed no clear link to injury. Single runs did. A run 10% to 30% longer than the longest run in the last 30 days raised injury risk by 64%. A run more than twice as long raised it by 128%.

Both studies looked at adults, not teens. The lesson still holds: watch each run, not just the weekly total. The step cycle gives steady growth with a planned break. The single-run limit keeps any one day from spiking.

Keep every run inside the 30-day ceiling

The single-run rule is simple. No run should go more than 10% past the longest run the athlete has done in the last 30 days. The 30-Day Ceiling Calculator does that math for one athlete at a time.

This planner keeps the long run at the same share of each week. So no build week pushes the long run past the ceiling. That only works if the athlete's real longest run is close to the week 1 Saturday number. If it is shorter, start with a lower weekly total.

Add new miles to easy days first

The table grows every day by the same share, the workout day included. When you write the real week, put new miles on easy days first. Tuesday's workout already carries load. Never raise volume and intensity in the same week. If you add a first tempo run, hold mileage flat that week.

For the full method, read how to increase mileage safely as a high school runner. For first-year athletes, see the freshman mileage progression guide.

Common questions

What should I enter as the starting number?

Enter what the athlete ran last week, or the average of the last two or three weeks. Use real numbers, not goal numbers. A plan built on a wish starts the athlete too high.

What if an athlete misses a week?

Repeat the previous week before you go on. Do not try to make up the lost miles.

How many weeks should I plan?

Eight to 16 weeks covers most base blocks. Because the table compounds, set a target peak too. The build stops there, and the rest of the plan holds with a cutback every fourth week.

Is the cutback week a wasted week?

No. The lighter week is where the body absorbs the work of the three weeks before it. Skip it, and the next build starts on tired legs.

Can one plan cover the whole team?

Only if the athletes start in the same place. A returning senior and a new freshman need different starting numbers. Run the tool once for each training group, or once for each athlete. If part of the team skipped summer, see what to do when half the team did not train.