Power to Weight Ratio Calculator

With Zwift racing and group rides the most important thing you need to know is what your watts per kilo because Zwift races and group rides are broken down into A, B, C, and D categories. These categories are based on your FTP and what the race / ride will average for the duration. Use our calculator below to determine your watts per kg at threshold and how that compares to each of the zwift racing categories.

Power to Weight Ratio

This will help you determine the best ride and category to join based on the training you are looking to get in. If you are in the base phase you should look more towards the group rides while approaching an interval plan can look at racing. Know if you are looking for a zone 2 type of effort or a sweet spot effort. Remember you can also ride in a lower category so it's not a full on racing effort. Make sure you know what course the event is taking place on. Is it flat? Climbing? This will also let you know the type of effort it may be. I find that if the course has some climbing it is far easier to get more sweet spot effort in. If it is flat you should be able to find a category to join or a group and roll mostly zone 2.


Most zone 2 group rides you will want to do will be a category lower than you race. So if your FTP falls in the A category look to do B paced group rides for moderate zone 2/3 work. If your FTP is in B category look for a C paced group ride. There are also pacer bots on course at all times that will follow a specific w/kg pace. You can join one of these groups on the Watopia world. A category is ridden at 4.0 w/kg, B is ridden at 3.2 w/kg, C is ridden at 2.5 w/kg and D is ridden at 1.5 w/kg. If you are looking to do a freestyle sweet spot ride choose the pacer that is one category higher than what you would for a zone 2 ride. 

One bonus to these events and races is that they will repeat on the same days or time. So get familiar with what events and races may work for particular training days.

Where is the best place to look at the group ride and race schedule? In App or a website?

Zwift companion app. Or the website. This goes with analyzing which we will get into. Riding with others, like an outdoor group ride, can be more motivating but only be effective if you let it work with your training. There are also time trial events. I find these to be the best to get in sweet spot or threshold workouts. They range from 15 - 30 minutes typical. Just very motivating again by completing an event start to finish as opposed to looking at a timer. Just important to not get carried away with your effort. Having the zone graph up while you race and really help you stay on track. Another great feature is the meetup feature. You can meet up friends and set up your own group ride or training.

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About Lacey Rivette

Lacey is a Registered Dietitian Nutritionist (RDN) with a Bachelor’s Degree in Nutrition And Dietetics from Louisiana State University. She trained as an acrobatic gymnastics from 2003-2013, during which time she won two national titles. It was also during this time that she became interested in sports nutrition and is what ultimately led her to pursuing a career in Dietetics. In 2018 she began racing MTB's in Louisiana and after getting on the podium at Marathon Nationals that same year, decided to move to Colorado Springs to be able to train more competitively. In 2020 she joined the FasCat team. When it comes to racing, her primary focus is on marathon, ultra endurance and adventure-style events.

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