A load estimation system and method for estimating vehicle load includes a tire rotation counter for generating a rotation count from rotation of a tire; apparatus for measuring distance travelled by the vehicle; an effective radius calculator for calculating effective radius of the tire from the distance travelled and the rotation count; and a load estimation calculator for calculating the load carried by the vehicle tire from the effective radius of the tire. A center of gravity height estimation may be made from an estimated total load carried by the tires supporting the vehicle pursuant to an estimation of effective radius for each tire and a calculated load carried by each tire from respective effective radii.