What is Power to Weight and Why Does it Matter?

Power to weight ratio, often expressed as watts per kilogram (W/kg), is one of the most important metrics in cycling performance. It represents how much power you can produce relative to your body weight.

Power to weight is especially important when climbing, because climbing speed is largely determined by how much power you can produce relative to the weight you are moving uphill.

Two cyclists producing the same power may perform very differently on climbs if one rider is lighter. Similarly, increasing power while maintaining body weight improves power to weight and usually improves climbing performance.

Power to weight is often calculated at different durations, such as:

• 5 seconds (sprint)

• 1 minute (anaerobic)

• 5 minutes (VO2 max)

• 20 minutes (threshold)

• 60 minutes (functional threshold power)

You can calculate your watts per kilogram using the Power to Weight Calculator on this site.

While power to weight is useful, it is not the only factor in cycling performance. Aerodynamics, rolling resistance, pacing and endurance all play important roles, especially on flat courses.

My performance coaching includes focus on cycling power, if I'm working with an athlete who trains for cycling races or triathlons.