The disclosure relates to an outer dimension measurement apparatus for tubulars. The apparatus includes a first wheel and a second wheel, which may be applied to different sections of a tubular. The ratio between the outer dimensions of the different sections may be estimated based on the relationship between the rates of rotations of the first and second wheels when the tubular is rotated. The apparatus may include a tubular rotation sensor that, with either the first wheel or the second wheel, may be used to determine the outer dimension of the tubular at the point along the tubular's length when the respective wheel is applied. The methods include estimating a ratio between outer dimensions of sections of a tubular and estimating the outer dimension of the tubular at a specific point along its length using embodiments of the apparatus.