Performance calculator

Your race, to the second

Swim pace, bike speed or watts, run pace, heat, wind, climbs, transitions. Choose km or miles for each leg and see your finish time, where it comes from and what to improve first.

Course

Load a race

Swim

Bike

Run

Weight · °

Swim distancemBike distancekmBike climbing (D+)mRun distancekmRun climbing (D+)mWater

Swim

Pool pace/100 mm:ssWetsuitSea stateStart

Bike

Describe your bike by

Flat speed, still airkm/hFTPWBody weightkgBike + kitkgPosition (CdA)Tyres and roadDescent speed capkm/hAverage windkm/h

Run

Flat pace, fresh legs/kmm:ssHeat-acclimated

Conditions

Temperature°CAltitudemT1m:ssT2m:ss

Finish time

5:48:17

Between 5:30:00 and 6:00:00

Swim	0:35:46	1:53 /100 m
Transitions	0:05:00	3:00 + 2:00
Bike	3:05:46	29.1 km/h
Run	2:01:45	5:44 /km

Open-water pace: 1:53 /100 m · 1:43 /100 yd
Flat-equivalent speed: 34.0 km/h · 21.1 mph
Power: 188 W · 2.51 W/kg · IF 0.75
Energy on the bike: 1,877 kJ ≈ 1,870 kcal
Carbs to plan: 464 g at 80 g/h over the whole race
Effective pace: 5:44 /km · 9:14 /mi
Bike fatigue · Heat · Altitude: +4.8 % · +2.8 % · +0.0 %
Climbing: +0:38

Where you land

4:305:005:306:006:307:15

Work backwards from a target

Enter the finish time you want. Swim, bike and run are scaled together and you get what each leg must be.

Finish time

What buys the most time

Small, realistic changes ranked by seconds saved on this course.

Run 10 s faster per km−3:48
+5 W on the bike−2:14
Heat acclimation−1:16
30 s less in each transition−1:00
Swim 3 s faster per 100 m−0:59
−1 kg body weight−0:27

Turn this time into a plan

Connect Garmin, Strava or Intervals and the plan is built on this course and your usual routes.

Build my plan

Alpha version: everything is free until 31 December 2026, workouts on your watch included. Early users help us fix what's broken.

An estimate from physics and published rules of thumb, not a promise: expect ±3-5 %. Heat, wind and climbing are modelled per course; pacing, nutrition and luck are up to you.