RunCalc+ is a very functional and useful calculator for runners. It will help you plan your training and track your progress. The app has many functions - pace and speed calculator - distance converter (imperial and metric units) - stride length - split times calculator(negative, positive and even) - race time predictor (based on your last run) - VO2max and vVO2max (using your race time) - age-grading (this will help you compare your results with runners of other sex and/or age) - racing weigh