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Normalised Power Calculator — NP from Average Power
Calculate normalised power from average power and variability index.
How We Calculate This
Normalised Power Formulas
- NP = Average Power x Variability Index
- Intensity Factor (IF) = NP / FTP
- TSS = (seconds x NP x IF) / (FTP x 3600) x 100
Note: True NP is calculated from 30-second rolling averages of power data. This calculator provides an estimate from average power and VI.
Frequently Asked Questions
Normalised Power accounts for the variability of your effort. A ride with surges and recoveries has a higher metabolic cost than steady riding at the same average power.
VI = Normalised Power / Average Power. A VI of 1.0 means perfectly steady. Criteriums may have VI of 1.3+. Road races typically 1.05-1.15.
IF = NP / FTP. An IF of 1.0 means you rode at your threshold. IF above 1.05 is unsustainable for long durations.
TSS = (duration_seconds x NP x IF) / (FTP x 3600) x 100. A 1-hour ride at FTP gives a TSS of 100.
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Last updated: February 2026
All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.