Calculators

The calculations Endu uses to build your plan, free to use: VMA, training paces, race time prediction, effort kilometres, heart rate zones, swim CSS, cycling FTP, triathlon times and race fuelling.

Free, no sign-up. Everything is computed in your browser: nothing you type here is sent anywhere.

VMA calculator

Work out your VMA from a race time or a 6-minute test and get your five training paces. Method explained, no sign-up.

VMA calculator

Training pace calculator

Your five paces in min/km from your VMA or a race time: easy, marathon, threshold, intervals, repetitions — each with its use.

Training pace calculator

Race time predictor

From a single race time, estimate your times on every distance from 5 km to 100 km, pace included. No exponent formula.

Race time predictor

Effort-kilometre calculator

Convert distance and elevation into flat kilometres, with the terrain coefficient and a time estimate. To compare a trail with a road race.

Effort-kilometre calculator

Heart rate zone calculator

Your five heart rate zones from the best data you have: heart rate reserve, threshold HR or max HR, using the Tanaka formula.

Heart rate zone calculator

CSS calculator (critical swim speed)

Work out your CSS from the 400 m and 200 m tests and get your six swim paces in min/100 m. For triathlon and swimrun.

CSS calculator (critical swim speed)

FTP and power zone calculator

Work out your FTP from a 20-minute test and get your six Coggan power zones, plus your watts per kilo.

FTP and power zone calculator

Triathlon time calculator

Estimate your total time and three splits, transitions and bike fatigue included, for sprint, olympic, 70.3 or Ironman.

Triathlon time calculator

Race fuelling calculator

How much carbohydrate per hour, at what rhythm to take it, and the list of what to buy and carry — computed with your own products, from a 10K to an ultra.

Race fuelling calculator

Now the plan that goes with it

These numbers are exactly the ones Endu uses to build a full preparation: phases, volume, detailed sessions, exported to your watch. 14-day trial, cancel any time.

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