ConverterHub

Weekly Mileage Build-Up Calculator

Get a full week-by-week ramp to your peak weekly mileage.

How it is calculated

Week 1 equals your current weekly volume. Each later normal week raises the running build level by your chosen percentage, never past the target: build = min(build × (1 + increase / 100), target). With the every-4th or every-3rd week option, those weeks are recovery weeks shown at 0.75 × the current build level (marked with *), and the build level does not change that week; the climb resumes the next week from the build level before the dip. The tool reports the peak week, whether and in which week the target is reached, the total volume of all weeks, and the safe step (current × increase / 100). Numbers are labelled km, though any distance unit works if used consistently. Weeks go from 1 to 52 and the target cannot be below current.

Worked example

Current 30 km per week, target 50 km, 10 weeks, 10 % increase, recovery every 4th week. Weeks 1 to 3 are 30.0, 33.0 and 36.3. Week 4 is recovery: 0.75 × 36.3 = 27.2. Week 5 resumes from 36.3: 39.9, then 43.9 and 48.3. Week 8 is recovery at 36.2. Week 9 would be 53.1, so it is capped at the target: 50.0, held in week 10. Peak week: 50.0 km, reached in week 9. Total volume over the ten weeks: 395 km. The safe step is 30 × 10 / 100 = 3.0 km.

Try this example →

Common mistakes

  • Entering miles and reading the results as kilometres. The calculation is unit-neutral, but the output is labelled km, so keep to one unit.
  • Treating the percentage as a fixed kilometre add-on. It compounds on the previous week, so week 3 adds 10 % of week 2, not of week 1.
  • Reading the starred recovery week as a mistake. It is a deliberate drop to 75 % of the current build level.
  • Setting a target the weeks cannot reach and ignoring the 'No' answer. Check the peak week in the result; with 4 weeks the same plan tops out at 39.9 km.
  • Setting the target below the current volume. The tool returns no plan, because it only builds upward.

About this calculator

Building weekly running mileage safely is governed by a widely cited but often oversimplified guideline — the '10 percent rule' — that caps how fast total weekly distance should rise so tendons, bones and connective tissue can adapt at the same pace as cardiovascular fitness. A proper build-up plan spaces steady increases with periodic recovery (or 'step-back') weeks, typically every third or fourth week, where mileage drops to 75% of the current build level (a 25% cut) before resuming the climb, rather than a straight uninterrupted ramp to peak volume.

Run coaches and self-coached marathoners use a structured build-up when returning from a break, moving up in race distance, or preparing a multi-month base-building block ahead of a training cycle, because uncapped week-over-week jumps in volume are one of the best-documented predictors of overuse injuries like stress fractures and tendinopathy. Capping the percentage increase and forcing in recovery weeks keeps the ramp aggressive enough to build fitness without outrunning the body's adaptation rate.

Was this helpful?

You can pick up to 3 reactions.

Comments

  • Be the first to comment.

Popular calculators

Loan Calculator

Monthly payment, total interest and full amortization schedule.

Percentage Calculator

Percent change, percent of, and ratio calculations.

Discount Calculator

Calculate final price, savings, and discount amount.

BMI Calculator

Body mass index from height and weight (metric or imperial).

Age Calculator

Compute your exact age in years, months and days from a birth date.

Compound Interest Calculator

Calculate the final amount and interest earned with compounding.

All Calculators