How much power do you need?

This is a mathematical equation that you can use to workout from past races how many watts needed for a set time. Please note that this only takes into account that everything is the same as the race info you input.

I will use myself for this example

Looking at my last Ironman bike of 5:14, if I want to take 14min off my time to have a bike split of 5hrs,

  • Normalized Power (NP): 193 watts
  • Bike Time: 5:14 (18,900 seconds)
  • 193 watts x 18,900 (5:14 in seconds) = 3647,700
  • 3647,700 ÷ 18,000 (5hr in seconds) = NP 202.65 watts giving a NP 9.65 watt difference (5.05% increase of NP)

So if I had rode that last Ironman at 203 watts instead of 193 watts, I would have got 5hrs bike split instead of 5:14.

Enjoy crunching numbers.


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