Sizing
Wetsuit size finderYour size in every brand Shoe size converterUK, US, EU and cm Bike frame calculatorRoad, mountain and hybrid
Swimming
Wetsuit thickness guideWhat to wear by water temp CSS calculatorCritical Swim Speed and zones Swim pace converterPool to open water, m and yd
Running
Race pace plannerSplits for your goal time Race time predictor5K to marathon from one result Hill effort converterGrade-adjusted pace Heart rate zonesFive zones, %max or Karvonen

Free sport tools

The right size, the right pace,
the right answer

Size finders, pace planners and training calculators for running, swimming and cycling.

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Sizing tools

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Wetsuit size finder

Every brand sizes differently, so the same swimmer can be four different letters. Enter your height and weight to see your size in Orca, Zone3, HUUB and Blueseventy at once.

Find my size →
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Shoe size converter

Convert between UK, US, EU and cm, or start from a foot measurement
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Bike frame calculator

Road, mountain and hybrid sizes from height and inseam

Swimming tools

Coach's pick

CSS calculator

Critical Swim Speed and training zones from two time trials
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Wetsuit thickness guide

What to wear for the water temperature
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Swim pace converter

Pool pace to open water, in metres and yards

Running tools

Race day

Race pace planner

Set a goal time and get every split laid out for you, with even pacing or a proper negative split in both km and miles.

Plan my race →
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Hill effort converter

See what that climb really cost you in flat pace terms
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Race time predictor

One result predicts your 5K to marathon times
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Heart rate zones

Five training zones from your max and resting heart rate