1 Hiring a contractor to pour a concrete sidewalk runs around $5-$9 a square foot, or $1,500-$2,250 for a sidewalk 5 feet wide and 50 feet long.2  Depending on the type of finish used, costs can be as high as $10-$18 or more a square foot, or $2,500-$4,500 for a 5-by-50-foot sidewalk. Depending on the type of finish used, costs can be as high as $10-$18 or more a square foot, or $2,500-$4,500 for a 5-by-50-foot sidewalk. 2  Materials and rental tools for a do-it-yourself project run about $3-$4 a square foot, or $750-$1,000 for a 5-by-50-foot sidewalk.