Enter a recent race of 800 m or longer. Sprint times are not used for training paces.
Race split calculator
Altitude race time converter
Estimate how your race time might compare between altitude and sea-level conditions.
Goal PR probability
Your chance of reaching a goal time by the end of the season.
A recent race (helps the estimate)
Compare three goals (same event)
College recruiting
These are estimates of how your times align with typical standards. They are not guarantees of recruitment, admission or a scholarship.
Data and limits
About Stride Factor
Our mission is to make the road from high school PRs to college running clear, honest and free for every runner.
What each tab offers
Predictions. Enter your PRs (800m, 1600m, 3200m, 5K, and 100m or 200m for sprinters) to see predicted times, a season range, and your strengths and profile. Distance predictions use your distance PRs; sprint PRs get their own sprint estimates.
Recruitment. Compare your PRs with college team standards and see which programs are a Match (within 4% of a standard, or faster) or a Potential Match (within 8%). Sprinters and distance runners are both supported. Save schools to a shortlist.
Goals. Pick a goal time and a deadline to see how likely a goal is. For 100m and 200m goals, you also see the gap to your PR, with a rougher estimate because it rests on assumed sprint parameters.
Tools. A training pace calculator for races of 400m and longer, a race split calculator (100m through 10K), and an altitude race time converter.
Accounts (optional). Everything above works without an account. A free account lets you save PRs, goals and predictions, and set a username and initials icon.
How We Get Our Results
Distance predictions start from the standard Riegel power-law equivalency between race distances, then blend it with a curve fitted through your own PRs. PRs close to the target distance and recent PRs count more. Weekly mileage only adjusts distances longer than your longest PR. Season ranges are a heuristic estimate of typical improvement, not a promise.
Sprints are not predicted with distance equivalency, which does not apply to them. 100m and 200m estimates use simple ratios between events. They ignore start, reaction time and wind, and are rough.
Recruitment compares each PR with the standards colleges publish (from college pages and Runcruit, used with permission) as a percentage difference. Your best single event decides the class. Where a college lists only a 5K standard, or you enter no sprint PR, comparisons use inferred or estimated numbers; these are labelled, ranked lower, and never rated better than Potential Match.
Goal chances come from a simulation that combines your fitness estimate, expected improvement and race-day variability.
Limits. These methods have not been scientifically validated, and we make no claim about their accuracy. College standards can change and were gathered from public pages, so confirm with each program. Nothing here guarantees a result, a roster spot, admission or a scholarship.
Fills 100m, 200m, 800m, 1600m, 3200m and 5K cross-country from your saved results.
Enter a PR, then select Predict my times, or try an example.
Model notes
Not scientifically validated. Established part: Riegel-style power-law equivalency (t₂ = t₁·(d₂/d₁)^k), here with k rising for shorter distances (1.10 / 1.08 / 1.07 / 1.06). Heuristic parts, all adjustable in the CAL object in the script: proximity weighting of PRs, the athlete-specific log-log curve through your own PRs, course factors (track 1.00, road 1.005, fast XC 1.02, average XC 1.035, difficult XC 1.07), conditions factors, the mileage exponent adjustment (±0.0006 per MPW from 40, capped ±0.012, applied only beyond your longest race distance so demonstrated endurance is not double-counted; beyond that distance a further +0.035 endurance-fade exponent is also added, scaled by how far out you go, because shorter-race PRs tend to overstate long-race ability), the confidence rules, and the potential ranges. Sex and workouts per week are collected but not used in the math. The XC 5K is converted to a track equivalent using your course type, then back to an average XC course for XC predictions.