Power-to-Weight Ratio for Cyclists: When Watts/kg Matters, and How to Improve It

Power-to-weight ratio reflects a cyclist’s ability to generate power, relative to their body weight. When used correctly, this metric can offer useful insights into training and help to show improvement over time. When used improperly, it can serve as an excuse for athletes to unhealthily obsess over weight. Let’s take a closer look at what power-to-weight ratio is (and isn’t), and how it can be viewed in the proper context to help you get faster.

Want to calculate your Watts/kg? Use our calculator.

What is Power-to-Weight Ratio (Watts per kilogram)?

Power-to-weight ratio is a measurement of your power on the bike, in comparison to your body weight. It is expressed as watts of cycling power produced per kilogram of body weight, abbreviated as W/kg. 

Larger riders tend to be more powerful than smaller cyclists in absolute terms, but lighter riders require less power to overcome inertia and propel themselves forward (especially uphill). Power-to-weight ratio thus offers a fairer way to compare the abilities of riders with varying body weights than by looking at power alone. More importantly, it also allows cyclists to better understand the nuance of their own cycling performance, as changes in fitness often occur in tandem with changes in body weight. 

What are the Watts in Watts per kilogram?

Watts are the standard measurement of power generated by a rider while riding a bike. While metrics such as heart rate and speed are subject to outside influence, power is objective and comparable in any condition. Technically speaking, a watt is a measurement of energy transfer and is measured in real-time while cycling with a power meter. Most commonly, the watts in W/kg refers to your sustainable power, (FTP).

FTP Testing

Knowing your power-to-weight ratio requires knowing your FTP, or functional threshold power. TrainerRoad uses AI to detect your FTP in the background, even if you aren’t doing all-out efforts. This means you’ll always have an accurate record of your W/kg for when it is useful. See what your FTP is now and begin your journey to getting faster!

What is my W/kg?

To calculate your W/kg, simply divide your FTP by your weight in kilograms. TrainerRoad displays your power-to-weight ratio using this formula at the top right of the career page. Or use our calculator.

Using your Power Curve

Power-to-weight ratio can also be useful to consider at other time durations, from short sprints to ultra-endurance rides. Finding your power-to-weight ratio for these time increments is the same as for FTP: divide your maximal power over your chosen time duration by your body weight in kg. You can then track changes over time as your weight and fitness varies.

To find your maximal power for other durations, use the Personal Records chart. By hovering your mouse over any point on the curve, you can see your best effort for that time frame.

Sample Power-to-Weight Ratios

The table below shows a sample range of power-to-weight ratios:

Weight	130W	160W	190W	210W	240W	270W	300W	330W	360W
100 lbs (45.4 kg)	2.86	3.52	4.18	4.62	5.28	5.95	6.60	7.26	7.92
120 lbs (54.4 kg)	2.39	2.94	3.49	3.86	4.41	4.96	5.51	6.06	6.61
140 lbs (63.5 kg)	2.04	2.51	2.99	3.30	3.77	4.25	4.72	5.19	5.66
160 lbs (72.6 kg)	1.79	2.20	2.61	2.89	3.30	3.71	4.13	4.54	4.95
180 lbs (81.6 kg)	1.59	1.96	2.32	2.57	2.94	3.30	3.67	4.04	4.41
200 lbs (90.7 kg)	1.43	1.76	2.09	2.31	2.64	2.97	3.30	3.63	3.96
220 lbs (99.8 kg)	1.30	1.60	1.90	2.10	2.40	2.70	3.00	3.30	3.60
240 lbs (108.9 kg)	1.19	1.46	1.74	1.92	2.20	2.47	2.75	3.03	3.30
260 lbs (117.9 kg)	1.10	1.35	1.61	1.78	2.03	2.29	2.54	2.79	3.05

When is Power-to-Weight Ratio important?

As a direct factor in performance, power-to-weight ratio is usually less important than you might think. Only on long and steep climbs does power-to-weight become the most important variable—terrain that is relatively uncommon in amateur cycling races. But bike racing at all levels is about conserving energy, and power-to-weight is still a factor. A small reduction in weight can make a big difference in cumulative effort over the course of a long cycling race. 

When is Power More Important Than Power-to-Weight?

On flat or rolling terrain, aerodynamics and raw power play a much bigger role than watts per kilogram. In fact, at racing speeds, almost 90% of a cyclist’s power is expended overcoming wind resistance. And while bigger cyclists do tend to have a larger profile in the wind, their increased resistance when compared to smaller cyclists is often outweighed by their superior ability to generate power. This is why larger and more powerful riders tend to win flat and windy races, while smaller climbers shelter in the pack. Simply put, in most situations, power is more important than power-to-weight.

Power-to-Weight as a Performance Metric

Apart from its direct implication on performance, power-to-weight is useful to track as a signifier of efficiency. A higher power-to-weight ratio indicates a greater proportion of lean muscle mass and a stronger aerobic engine. So, while your W/kg does directly influence your climbing ability, it’s also a good indication of general fitness and body composition as it relates to cycling. 

Training to Improve W/kg

There are two ways to improve your power-to-weight ratio: by increasing power, and by decreasing weight. Sometimes the two go hand-in-hand, but not always. 

Increasing Power

Since aerodynamics and raw power are generally more important than weight, increasing your ability to generate power can have a huge impact. The simplest way to do this is by following a structured training plan. TrainerRoad makes that easy, and with Plan Builder your training will specifically target the fitness you need to reach your goals.

As you get fitter your sustainable power will increase, and your power-to-weight ratio will improve. But getting stronger is only half the battle, and many athletes also address the other half of the W/kg equation: weight.

Decreasing Weight

Losing excess fat while increasing power is the holy grail of training. While most athletes naturally lose some weight over the course of a training plan, many of us also try other strategies for additional weight loss. If you decide to go this route, avoid dramatically cutting calories and instead prioritize consistent training and sensible eating to fuel your workouts and recovery. 

A fixation on weight and skinniness is dangerously common in cycling. High power-to-weight ratios signify efficiency and optimal body composition, and this does not necessarily mean lighter or skinnier. Excessive weight loss negatively affects power-to-weight ratio by reducing muscle mass, and many riders are proportionally more powerful at a slightly higher weight. 

Consider weight loss in the context of making yourself healthier, rather than chasing it as an end in and of itself. Your current body composition may make sensible weight loss a beneficial target for watt/kg improvement, but if you are already very lean it may bring diminishing returns and should take a back seat to improvements in power. 

What is a Good W/KG?

Power-to-weight ratios vary across a wide spectrum. Generally, untrained riders have an FTP below 2.0 W/kg for men and 1.5 W/kg for women, while professional racers may be capable of sustaining more than 6.0 W/kg for men and 5.5 for women. The majority of TrainerRoad athletes have power-to-weight ratios between 2.25 W/kg and 3.5 W/kg, but many of our athletes sit well above or below this range. 

Wherever your current W/kg, take heart. Almost everyone can significantly improve their power-to-weight ratio with structured training. How much improvement to expect depends on a number of factors, including available training time, experience level, age, and genetics, among others. Your goals should play a role in determining your expectations- how fit do you need to be to achieve success in your target event? Winning the local crit won’t require a pro-level power-to-weight ratio, but might be just the goal you need to push yourself to the next level. 

Beginner Cyclist? Start here!

The most impactful and sustainable way for a beginner cyclist to improve your power-to-weight ratio is by focusing on raising your functional threshold power (FTP) while allowing your body weight to adjust naturally.

TrainerRoad’s AI-driven cycling training plans are designed to make you faster and increase your FTP. With proven interval and threshold training, your personalized training plan adapts as you progress, ensuring consistent, measurable improvements that last.

Start improving your power-to-weight ratio and unlock your fastest cycling yet—Get started today!

Elite Cyclist? Here’s How to Optimize Your Diet for a Better W/kg

Improving your power-to-weight ratio (W/kg) isn’t about extreme dieting—it’s about sustainable, results-driven habits. Consistent interval training and balanced nutrition are key to raising your functional threshold power (FTP) and optimizing your body weight for cycling performance. Aggressive calorie cutting can lead to fatigue, poor recovery, and decreased training quality, ultimately hindering your W/kg progress.

Nutrition Principles for Cyclists (from Dr. Kyle Pfaffenbach):

• Protein: Consume 1.4–1.8g of protein per kg of body weight daily to support muscle repair and recovery.
• Fat: Include at least 1.2g of fat per kg of body weight daily to maintain hormonal health
• Carbohydrates: Start by calculating your basal metabolic rate. Once your protein and fat requirements are met, allocate the rest of your daily intake to carbohydrates. Adjust your carbohydrate intake as needed based on training performance, energy levels, and weight trends.

TrainerRoad’s personalized cycling training plans help you achieve your best power-to-weight ratio yet by combining proven interval and threshold training with precise AI-driven adaptations to keep your progress on track. Ready to see your W/kg take off? Try TrainerRoad today!

Learn More with Dr. Kyle Pfaffenbach

Check out these insightful discussions from the Ask a Cycling Coach Podcast:

• High Carb Adaptation and Limits – Episode 469
• Protein for Cyclists and Sodium Loading – Episode 479
• Late Night Workouts: Scientific Deep Dive – Episode 458
• Recovery Week Nutrition for Cyclists – Episode 493