A weighing system comprising: a conveyor belt (12; 56) arranged to advance in a travel direction along a travel path from an upstream end to a downstream end and having a plurality of article-supporting rollers (18; 50; 58) actuatable to rotate toward a side of the conveyor belt (12; 56) in a transverse direction transverse to the travel direction; a weighing zone extending along a first length of the travel path in which one or more weight sensors measure the weights of articles conveyed by the conveyor belt (12; 56) and produce weight signals indicative of the weights of the articles; a roller-actuation zone extending along a second length of the travel path; wherein, in the roller-actuation zone, an actuator selectively actuates the article-supporting rollers (18; 50; 58) as they pass through to push articles in the transverse direction; characterised in that the weighing system comprises a controller: receiving the weight signals; determining the weights of the articles from the weight signals; selectively actuating and deactuating the rollers (18; 50; 58) passing through the roller-actuation zone as a function of the weights of the articles; wherein the weight sensors are coupled to the rollers (18; 50; 58) to measure the downward forces on the rollers (18; 50; 58) applied by the conveyed articles atop the rollers (18; 50), the weight signals being proportional to the downward forces. a conveyor belt (12; 56) arranged to advance in a travel direction along a travel path from an upstream end to a downstream end and having a plurality of article-supporting rollers (18; 50; 58) actuatable to rotate toward a side of the conveyor belt (12; 56) in a transverse direction transverse to the travel direction; a weighing zone extending along a first length of the travel path in which one or more weight sensors measure the weights of articles conveyed by the conveyor belt (12; 56) and produce weight signals indicative of the weights of the articles; a roller-actuation zone extending along a second length of the travel path; wherein, in the roller-actuation zone, an actuator selectively actuates the article-supporting rollers (18; 50; 58) as they pass through to push articles in the transverse direction; characterised in that the weighing system comprises a controller: receiving the weight signals; determining the weights of the articles from the weight signals; selectively actuating and deactuating the rollers (18; 50; 58) passing through the roller-actuation zone as a function of the weights of the articles; wherein the weight sensors are coupled to the rollers (18; 50; 58) to measure the downward forces on the rollers (18; 50; 58) applied by the conveyed articles atop the rollers (18; 50), the weight signals being proportional to the downward forces. receiving the weight signals; determining the weights of the articles from the weight signals; selectively actuating and deactuating the rollers (18; 50; 58) passing through the roller-actuation zone as a function of the weights of the articles; wherein the weight sensors are coupled to the rollers (18; 50; 58) to measure the downward forces on the rollers (18; 50; 58) applied by the conveyed articles atop the rollers (18; 50), the weight signals being proportional to the downward forces.