UCI regulations govern the maximum distance that the cycle can travel in one complete turn of the pedals. e.g. Age 10 max progressive metres is 5.4 mts. The formula to calculate progressive is ( Number of chainring teeth / Number of sprocket teeth ) x Outside circumference of wheel. With this calculator you can quickly calculate the progressive metres then if required alter the three variables of tyre, chainring and sprocket size to obtain the optimum progressive metres for the age of the rider.

Simply select a tyre size from the available list, select an age group from the list, enter chainring and smallest sprocket size then calculate.

If your tyre size is not available use the next size up for the calculation.

At time of publication the outside circumference of available tyres were correct as were the UCI maximum progressive metres regulations regarding age groups