Speed in Zwift and Real speed

Advance I am sorry for possible mistakes, English is not my native language.

Has anyone compared the speed in Zwift with speed in real life? Of course we are not talking about virtual power, but only of those who have the real power meter data. Maybe someone riding in Richmond on the same sections?


Zwift has no head or tailwinds. Aerodynamics will also vary as your avatar may not be positioned on the bike as your physical self, or wearing similar style of cycling clothing. And furthermore, Zwift is free of cars and traffic lights.

As such, comparing may be challenging.

Personally, I also don’t think it’s relevant. What matters mostly is that the progress you make in Zwift in terms of power levels you produce will translate into increased power levels riding outdoors.

A primitive comparison would be to compare a flat, low wind, road ride with a heart rate of x to a similar ride with the same average heart rate on Zwift.

Just started using Zwift in the past week. What I will say is that on the WC course, I go about 10% faster for the same wattage that I do on a flat road with no wind. And the wattage lines up with what I would expect from HR or perceived effort.

As a comparison, I found myself going 23-24mph on flats while putting out 220 watts - I weigh 166 pounds. This is with no powerups. In real life, I have to put out more like 260-270 watts to steadily go 24 mph, and that’s on my TT bike. Obviously this could be because I am incredibly inefficient outdoors except these numbers aren’t too far off the norms I’ve seen. So my conclusion is that on average, Zwift is overestimating my speed.

All that said, I agree with Stef Levolger that it really doesn’t matter. I am basing my training evaluation on watts and duration, not miles/miles per hour.

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