A system comprising: a predefined reference pattern comprising a plurality of optically perceptible elements (62, 64), the optically perceptible elements comprising at least a first optically perceptible element and a second optically perceptible element, wherein the first optically perceptible element has a first predefined dimension (a), wherein the second optically perceptible element has a second predefined dimension (c), wherein the first optically perceptible element and the second optically perceptible element are separated from each other by a first predefined distance; and a dimensioner (20, 24, 36) configured to: determine at least one dimension of an object (16, 40); measure the first predefined dimension (a) from one or more images of the predefined reference pattern captured by the dimensioner (20, 24, 36); measure the first predefined distance between the first optically perceptible element and the second optically perceptible element; calculate a first ratio of the measured first predefined dimension (a) of the first optically perceptible element and the measured first predefined distance; measure the second predefined dimension (c) from one or more images of the predefined reference pattern captured by the dimensioner (20, 24, 36); calculate a second ratio of the measured second predefined dimension (c) of the second optically perceptible element and the measured first predefined distance; wherein the dimensioner (20, 24, 36) is further configured to be calibrated based on the calculated first ratio and the calculated second ratio. a predefined reference pattern comprising a plurality of optically perceptible elements (62, 64), the optically perceptible elements comprising at least a first optically perceptible element and a second optically perceptible element, wherein the first optically perceptible element has a first predefined dimension (a), wherein the second optically perceptible element has a second predefined dimension (c), wherein the first optically perceptible element and the second optically perceptible element are separated from each other by a first predefined distance; and a dimensioner (20, 24, 36) configured to: determine at least one dimension of an object (16, 40); wherein the first optically perceptible element has a first predefined dimension (a), wherein the second optically perceptible element has a second predefined dimension (c), wherein the first optically perceptible element and the second optically perceptible element are separated from each other by a first predefined distance; and a dimensioner (20, 24, 36) configured to: determine at least one dimension of an object (16, 40); measure the first predefined dimension (a) from one or more images of the predefined reference pattern captured by the dimensioner (20, 24, 36); measure the first predefined distance between the first optically perceptible element and the second optically perceptible element; calculate a first ratio of the measured first predefined dimension (a) of the first optically perceptible element and the measured first predefined distance; measure the second predefined dimension (c) from one or more images of the predefined reference pattern captured by the dimensioner (20, 24, 36); calculate a second ratio of the measured second predefined dimension (c) of the second optically perceptible element and the measured first predefined distance; wherein the dimensioner (20, 24, 36) is further configured to be calibrated based on the calculated first ratio and the calculated second ratio.