Concept2 Weight Adjustment Calculator
By the Watta Team · Updated
Enter a time and your body weight to get the Concept2 weight-adjusted time. A 70 kg rower's 7:00 2K adjusts to 6:11; a 95 kg rower's to 6:37.
Weight Adjustment
Concept2 formula: corrected time = actual time × (weight ÷ reference)^0.222, with a 270 lb (122.5 kg) reference. Lighter than the reference gives a faster adjusted time.
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What a 7:00 2K is worth at different body weights
Computed with the same functions as the calculator above, so the two cannot disagree.
| Body weight | Weight factor | Adjusted 7:00 2K | Adjusted 7:30 2K |
|---|---|---|---|
| 55 kg | 0.837 | 5:52 | 6:17 |
| 65 kg | 0.869 | 6:05 | 6:31 |
| 75 kg | 0.897 | 6:17 | 6:44 |
| 85 kg | 0.922 | 6:27 | 6:55 |
| 95 kg | 0.945 | 6:37 | 7:05 |
| 105 kg | 0.966 | 6:46 | 7:15 |
Concept2's reference weight is 270 lb (122.5 kg), so every adjusted time is faster than the raw one. The adjustment compares rowers, it does not change what happened on the machine.
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About This Calculator
The Concept2 weight adjustment calculator normalises rowing ergometer performance for body weight so that rowers of different sizes can be compared. Heavier athletes have a natural advantage on the erg because they can apply more force per stroke, but they also have more mass to carry in a boat. Concept2's formula estimates what each rower's time would be worth in a boat by scaling it to a reference weight of 270 lb (122.5 kg): weight factor = (body weight ÷ 270 lb)^0.222, and corrected time = weight factor × actual time. Because almost everyone weighs less than 270 lb, almost everyone's adjusted time is faster than their actual time — the lighter the rower, the bigger the credit. Concept2 uses the same reference for men and women.
How This Works
Enter your time and your body weight. The calculator computes the Concept2 weight factor, (weight ÷ reference)^0.222, and multiplies your time by it. The reference defaults to Concept2's 270 lb; you can change it to compare against a different standard (for example 75 kg), but only the 270 lb version matches the figures on Concept2's own calculator and its weight-adjusted rankings.
Formula
Examples
A 70 kg rower pulls a 7:00 2K
Weight factor 0.883; adjusted time 6:11 — 49 seconds of credit against the 270 lb reference.
A 95 kg rower pulls the same 7:00 2K
Weight factor 0.945; adjusted time 6:37. Still faster than 7:00, but with 23 seconds of credit rather than 49 — the lighter rower's 7:00 ranks higher.
A 60 kg rower pulls a 7:45 2K
Weight factor 0.854; adjusted time 6:37 — the same weight-adjusted score as the 95 kg rower's 7:00, from a raw time 45 seconds slower.
Worked examples are generated from the same formulas as the calculator above.
Benchmarks
| Level | Value |
|---|---|
| 60 kg | factor 0.854 — 7:00 → 5:58 |
| 70 kg | factor 0.883 — 7:00 → 6:11 |
| 80 kg | factor 0.910 — 7:00 → 6:22 |
| 90 kg | factor 0.934 — 7:00 → 6:32 |
| 100 kg | factor 0.956 — 7:00 → 6:42 |
| Reference (122.5 kg / 270 lb) | factor 1.000 — time unchanged |
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 stores your body weight in your profile and uses it in the Work Output part of the Effort Score. It does not currently display a Concept2 weight-adjusted time — use this page for that.
Frequently Asked Questions
How does the Concept2 weight adjustment work?
Why does a lighter rower get a faster adjusted time?
Is weight-adjusted time used for team selection?
What is the reference weight for the Concept2 adjustment?
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