2K Time Predictor

By the Watta Team · Updated

Enter a recent result at another distance and get a 2K prediction using Paul's Law. A 19:10 5K (1:55.0 split) predicts a 2K of about 7:14.

2K Time Predictor

minsec
Predicted 2K Time7:101:47.4 /500m, from 1:54.0 /500m over 5000m

Paul's Law: about 5 seconds per 500m slower for every doubling of distance. A rule of thumb for trained rowers — your own aerobic/anaerobic balance can move the result by several seconds per 500m.

Rowing this later? Watta logs the real piece from a photo of your PM5 — free on iPhone.

The 2K a 5K result predicts

Computed with the same functions as the calculator above, so the two cannot disagree.

5K timePredicted 2K2K split
18:006:461:41.4
19:007:101:47.4
20:007:341:53.4
22:008:222:05.4
24:009:102:17.4

Paul's Law: the sustainable split changes by about 5 seconds per 500m for every doubling or halving of distance. It is a rule of thumb, not a measurement — a sprinter beats it over 2K and an endurance rower does not.

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About This Calculator

The 2K time predictor estimates your 2,000-metre rowing ergometer performance from a result at another distance. The 2K erg test is the standard benchmark in rowing, typically taking 6 to 8 minutes and requiring near-maximal aerobic and anaerobic output. The prediction uses Paul's Law, the rule of thumb that a rower's sustainable /500m split slows by about 5 seconds for every doubling of distance — and speeds up by 5 seconds for every halving. From 5K to 2K that is 2.5 halvings-worth, so a 5K split of 1:55.0 predicts a 2K split of about 1:48.4. Individual results vary with an athlete's aerobic-anaerobic balance, so treat the output as a target range rather than a guarantee.

How This Works

Enter a recent maximal result from a known distance (500m, 1K, 5K, 6K or 10K). The calculator converts it to a /500m split, adjusts that split by 5 seconds for every doubling or halving of distance between the known distance and 2,000m (Paul's Law), and converts the adjusted split back to a finish time. For best accuracy, use a result from a genuine maximal effort within the last 4–8 weeks.

Formula

Predicted split = known split + 5 × log₂(2000 / known distance); Predicted time = predicted split × 2000 / 500

Examples

Your 5K is 19:10 (1:55.0/500m)

Your predicted 2K time is approximately 7:14 (1:48.4/500m).

You hold a 2:05.0 split for a 6K (25:00)

Your predicted 2K is approximately 7:48 (1:57.1/500m).

You rowed a 1:38.0 1K (3:16)

Your predicted 2K is approximately 6:52 (1:43.0/500m) — one doubling of distance, so 5 seconds per 500m slower.

Worked examples are generated from the same formulas as the calculator above.

Benchmarks

LevelValue
Recreational male7:30–8:30
Club male6:40–7:20
Collegiate male6:05–6:35
Recreational female8:30–9:30
Elite female6:40–7:10

More reference tables — 2K, 5K and 500m standards, watts by level, stroke rates and a split-to-watts table — are on the Stats & Benchmarks page.

In the Watta App

Watta keeps a personal best for each standard distance on each machine, so once you have logged a real 2K you can check the prediction against it.

Frequently Asked Questions

How do I predict my 2K time from a 5K?
Paul's Law takes about 6.6 seconds per 500m off a 5K split to get a 2K split (5 seconds per halving of distance, and 5K to 2K is 1.32 halvings). If your 5K split is 1:55.0 (a 19:10 5K), your predicted 2K split is about 1:48.4, for a 2K of around 7:14. The common shortcut of "subtract 5 seconds per 500m" gives a slightly more conservative 7:20.
How accurate are 2K predictions?
Predictions from 5K or 6K results are usually within a few seconds for trained rowers who have done a genuine maximal test, because those distances rely on similar energy systems. Predictions from very short pieces (500m) or very long ones (half marathon) are less reliable. Paul's Law is a rule of thumb, not a physiological measurement.
Can I predict my 2K from steady state splits?
Only roughly. Steady state is not a maximal effort, so it does not fit the rule. As a general guide, 2K pace is 15–25 seconds per 500m faster than a comfortable UT2 split, but this varies a lot with fitness, rate capability and experience. A recent 5K or 6K test gives a far better prediction.
Why is the 2K erg test so important in rowing?
The 2K is the standard selection metric used by most rowing programmes worldwide. It tests the combination of aerobic power, anaerobic capacity and pacing discipline that correlates strongly with on-water performance, so university, club and national-team selection commonly use it.

Related Content

5K Time PredictorRowing Pace CalculatorSplit to Watts Converter10K Time Predictor2K TestA 2K test is a 2,000-metre maximal effort rowing ergometer test — the standard benchmark for indoor rowing performance, used for team selection and fitness assessment.VO2 Max (Rowing)VO2 max in rowing is the maximum rate of oxygen your body can use during exercise, measured in mL/kg/min, and is the strongest predictor of endurance rowing performance.Split TimeSplit time is the pace expressed as the time it takes to row 500 metres on an ergometer, displayed in minutes and seconds (e.g. 2:00.0/500m).2K Rowing Test Guide

Which Rowing App Should You Use?

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