Schools Indoor Rowing League

Children in Need Row 2026, 2 to 13 November. £5,949 raised by 9 teams so far.

Compete

Handicapping and adjustment factors

How weight and age adjustments work, so that rowers of different sizes and ages can be compared fairly.

Weight adjustment factor

The weight adjustment factor (WAF) for weight correction is (weight in kilogrammes ÷ 77.27)2/9.

For timed pieces, corrected time is the actual time multiplied by the WAF. For distance pieces, the corrected distance is the actual distance divided by the WAF.

WeightFactorWeightFactorWeightFactorWeightFactor
50.0kg0.90867.5kg0.97182.5kg1.01597.5kg1.053
52.5kg0.91870.0kg0.97985.0kg1.022100.0kg1.059
57.5kg0.93772.5kg0.98787.5kg1.028102.5kg1.065
60.0kg0.94675.0kg0.99490.0kg1.035105.0kg1.071
62.5kg0.95477.5kg1.00192.5kg1.041107.5kg1.076
65.0kg0.96380.0kg1.00895.0kg1.047110.0kg1.082

Alternative WAF

Concept2's US website uses a different weight adjustment factor: in the formula above, substitute 122.73 for 77.27.

Originally, we used 77.27 to normalize the weight adjusted scores because 77.27kg (170lb) was approximately the average weight of all rowers. But about a year ago we realized that by using a different number to normalize the weight adjusted score we could give the adjusted score more meaning. By using 122.73, the weight adjusted score becomes a pretty good estimate of a person's potential speed in an eight. To put it another way, if the average adjusted score using this formula of the 8 rowers in an eight is 6:00, then that boat should be capable of a 6:00 2k race on the water, given perfect conditions and near perfect rowing effectiveness (nobody rows perfectly). We believe that this will be approximately true for all types of crews.

This isn't so relevant for the average indoor rower, so it isn't generally used for adjusting results, but it may be an interesting comparison for some.

Age adjustment

Age adjustment is based on the following formulae, which come from research by Eddie Fletcher of Fletcher Sports Science:

  • Men: performance is held to decline by 0.12% a year from the ages of 26 to 55, and by 0.83% a year from age 56 onwards.
  • Women: performance is held to decline by 0.23% a year from the ages of 26 to 55, and by 0.74% a year from age 56 onwards.