Watts per kilogram determines climbing speed; FTP is the power you can hold for about an hour.
How to use the Cycling Power and W/kg Calculator
- FTP
- Body weight
- Bike and kit weight
Results update as you type, and every field accepts the units shown in its menu.
How it works
Divide power by weight; zone limits are percentages of FTP (Coggan model).
Inputs explained
| Field | What to enter |
|---|---|
| FTP | In W |
| Body weight | Units: kg, lb, g, oz, st |
| Bike and kit weight | Units: kg, lb, g, oz, st |
What each result means
- Power-to-weight = [FTP]÷[Body weight]
- Including bike = [FTP]÷([Body weight] + [Bike and kit weight])
- Endurance zone up to = [FTP]×0.75
- Threshold zone up to = [FTP]×1.05
Example values
How the main result changes when FTP changes and everything else stays at the example values above:
| FTP (W) | Power-to-weight (W/kg) |
|---|---|
| 125 | 1.74 |
| 187.5 | 2.6 |
| 250 | 3.47 |
| 312.5 | 4.34 |
| 375 | 5.21 |
| 500 | 6.94 |
Formula
W/kg = power ÷ body weightZones: Z2 56–75%, Z3 76–90%, Z4 91–105% of FTPWorked example
Inputs — FTP: 250 W; Body weight: 72 kg; Bike and kit weight: 9 kg.
Results — Power-to-weight = 3.47 W/kg; Including bike = 3.09 W/kg; Endurance zone up to = 188 W; Threshold zone up to = 263 W.
Frequently asked questions
What is a good FTP?
Around 3 W/kg is typical for fit amateurs; pros exceed 5.5 W/kg.
How do I test FTP?
A common test is 95% of your average power over 20 minutes.
What formula does the Cycling Power and W/kg Calculator use?
W/kg = power ÷ body weight.