Calculator
TSS Calculator
Quantify your training load. Calculate Training Stress Score to measure the physiological cost of every ride.
The Formula
TSS = (sec × NP × IF) / (FTP × 3600) × 100
secDuration in seconds
NPNormalized Power
IFIntensity Factor (NP / FTP)
FTPFunctional Threshold Power
Typical TSS Values
< 150
Low
Recovery complete by next day
150–300
Medium
Residual fatigue may persist 1–2 days
300–450
High
Some fatigue may last 2+ days
> 450
Very High
Residual fatigue lasting several days