Question 1

What is W/kg in cycling?

Accepted Answer

W/kg is the ratio of your sustainable power output (typically FTP) to your body weight. It's the cleanest single number for comparing cyclists across body sizes — a 60 kg rider at 240 W (4.0 W/kg) climbs about as fast as a 90 kg rider at 360 W (4.0 W/kg).

Question 2

Which W/kg category am I in on Zwift?

Accepted Answer

Zwift's legacy W/kg buckets are: A+ (≥4.6), A (4.0–4.59), B (3.2–3.99), C (2.5–3.19), D (under 2.5). Note: Zwift now uses a Racing Score system for matchmaking, but the W/kg buckets remain the most-used self-classification.

Question 3

How do I move up a cycling category?

Accepted Answer

Two levers: gain watts (raise FTP through structured training) or lose body weight. The math is symmetric — what matters is your W/kg. Realistic monthly FTP gains depend on training age: 4–10 W/month for untrained riders, dropping to 1–3 W/month for already-very-good athletes.

Watts per kilo & cycling category

How to climb a category