Running calculators
They all run on a single screen, need no account and keep the result in the address bar, so you can save it or send it to a training partner.
Pace calculatorDistance, time and pacePace convertermin/km, min/mile, km/h, mphGrade adjusted paceWhat a hill costs youGPX course analysisUpload a GPX, get the planCycling power zonesFTP, W/kg and 7 zonesSwim paceCSS and 100 m pacesHYROX time planFinish estimate and station splitHeart rate zonesRange for the five zonesTrail effort distanceTurn climbing into flat kilometresHydration needsHourly fluid and sodium planRace fuellingHourly carbohydrate planCycling nutritionCarbs per hour and bottle planRace time predictorOne result, other distancesSplit tableKilometre splits for a goal timeTraining pacesPaces from a race resultCutoff planCheckpoint arrivals and buffer time
These are general ranges and assume normal conditions. Trail, heat, elevation gain, wind and technical ground all make the real time longer.