Multi-Sport TSS Calculator
Get the Training Stress Score and Intensity Factor for a single session across all four disciplines — power for the bike, pace for the run, CSS for the swim, heart rate as a fallback — using the same math PaceBeats scores your real workouts with.
Sport
Training Stress Score
71
Intensity factor
0.84
Method
Power (NP / FTP)
How to use it
- 1Choose the sport: bike, run, swim, or strength.
- 2Enter the session duration.
- 3Add the intensity input for that sport — average/normalized power and FTP for the bike, average and threshold pace for the run, distance and CSS for the swim.
- 4No power or pace? Switch to heart rate and enter average HR and your LTHR.
- 5Read the TSS, Intensity Factor, and the method used to compute it.
One calculator, every discipline
Most TSS calculators only handle bike power. This one picks the best method per sport: normalized power against FTP for the bike, threshold pace for the run, critical swim speed for the swim, and heart rate against LTHR when that's all you have. Each method returns both TSS and the underlying Intensity Factor so you can see how hard the session really was, not just how long.
Hilly runs score correctly
Flat-pace TSS under-counts a hard hill session. Enter your elevation gain and the run method applies a grade-adjusted pace (Minetti's energy-cost-of-running model — each 1% of average grade adds about 8% to the effort), so a climb-heavy run gets the stress score it earned.
The building block of fitness and form
TSS is the raw input behind CTL, ATL, and TSB — your fitness, fatigue, and form. Score your sessions here, then feed those numbers into the Fitness, Fatigue & Form chart to see how a week of training moves your readiness for race day.
How the math works
Bike: TSS = (sec × NP × IF) / (FTP × 3600) × 100, IF = NP/FTP. Run: rTSS = (sec × IF²)/3600 × 100, IF = threshold pace ÷ average pace, with optional grade-adjusted pace from elevation gain. Swim: sTSS = (sec × (CSS/pace)³)/3600 × 100. Heart rate: hrTSS = hours × (avgHR/LTHR)² × 100. Strength is a flat 50 TSS/hour. These are the identical formulas in the PaceBeats engine, so a session scores the same here as it does inside the app.
Built and reviewed by the PaceBeats coaching-engine team. Every calculator runs the same sports-science math that powers the app's adaptive plans.
Common questions
What's a good weekly TSS for triathlon?
It depends entirely on your distance, experience, and available hours rather than a universal number. As a rough orientation, many age-groupers peak around 400–500 weekly TSS for a 70.3 and 650–850 for an Ironman. The training-hours reality check turns your available hours into a realistic target.
Do I need a power meter to calculate TSS?
No. A power meter gives the most accurate bike TSS, but you can use pace for running, CSS for swimming, and heart rate as a fallback for any sport. This calculator automatically uses the best method for the data you have.
Next step
Turn these numbers into an adaptive plan.
PaceBeats uses this exact math — and your training history — to build and adapt your swim, bike, run, and strength week after week.