From a 1K to your
2K target

Within ~5–10 seconds for most athletes when the right profile is selected. Athletes with deeper aerobic bases hold pace better than the model assumes for their tier and beat the prediction; power-dominant athletes who haven't developed their aerobic engine usually fall behind it. Pick the profile that fits your training history for the best fit.

Direct multiplier model: 2K time = 1K time × 2 × multiplier. The multiplier reflects how much your average split degrades from a max 1K to a max 2K — bigger multiplier = bigger drop-off = less aerobic capacity. Equivalent to a Riegel endurance exponent k where k = 1 + log₂(multiplier), but the multiplier form is easier to read in the dropdown.

Elite / National — senior international team or top D1, 3+ years of high-volume aerobic training, sub-6:00 men / sub-6:50 women 2K. Competitive — strong club / D1 / national-level college athlete. Club / Collegiate — typical collegiate or solid masters competitor. Recreational — fitness-focused or developing junior, 1K is more anaerobic-biased than your 2K race.

A 1K piece is heavily anaerobic-lactic — you can hold a power output well above your aerobic ceiling for ~3 minutes. Going to 2K (~6 minutes) requires far more aerobic contribution. Athletes with smaller aerobic engines lose more of their 1K speed when they double the distance, so their multiplier is higher.

It's a quick mental-math heuristic that lands close to the Competitive tier for typical splits. For a 3:00 1K it gives 6:30; the Competitive multiplier here gives 3:00 × 2 × 1.108 = 6:39 — within a few seconds. The multiplier model handles outliers (very fast or very slow 1K times) more honestly because it scales proportionally instead of adding a flat 30s regardless of pace.

Useful as a benchmark, not as a substitute. The 1K is anaerobically biased, so it tells you about top-end power; the 2K is aerobically biased, so it tells you about your engine. Use the 1K → 2K estimate to set a 2K target split, then race the 2K to validate.