A study was conducted to determine feeder space requirement for growing and finishing pigs based on the amount of time needed to maintain their feed intake and growth performance. The first trial used 16 pens of 12 pigs. Four pens were randomly assigned to each of 4 treatment combinations: mash diets fed from a dry feeder (DM), mash diets fed from a wet/dry feeder (WM), pelleted diets fed from a dry feeder (DP) and pelleted diets fed from a wet/dry feeder (WP). Both the dry and wet/dry feeder provided single feeding space and were similar in design. Eating behavior was video-recorded for 24 h in all pens when pigs were 35 to 45 kg and 90 to 100 kg, respectively. The videos were analyzed using scan-sampling at 5-min intervals to determine time spent eating for each size of pigs. In the second trial, 564 pigs in 32 pens were used to evaluate 4 levels (80%, 95%, 110%, and 125%) of feeder capacity for growing and finishing pigs, with 2 pens assigned to each level of feeder capacity under the same treatments. Feeder capacity was defined 100% when the feeder was expected to be used 100% of the time by pigs according to the eating behavioral data from trial one. The different levels of feeder capacity were generated by varying the number of pigs in a pen and modifying the pen size accordingly to maintain floor space allowance consistent cross treatments. Pigs fed WM spent less time eating (72 vs. 107 min/pig/d for growers, SE = 2.68; P < 0.001) and 67 vs. 106 min/pig/d for finishers, SE = 3.39; P < 0.001) compared with pigs fed DM. Likewise, pigs fed DP spent less time eating than pigs fed DM (P < 0.001) during both growing and finishing phases. There was no difference in total duration of eating between pigs fed DP and WP. Cross treatments, ADG decreased from 793 to 693 g during the grower phase (SE = 9; P < 0.001) and from 941 to 667 g (SE = 27; P < 0.001) during the finishing phase when feeder capacity increased from 80 to 125%, respectively. To maintain 80% feeder capacity, the estimated feeder requirement is 11 pigs per feeder space for pigs fed DM during both growing and finishing phases. For pigs fed WM, DP or WP diets, the estimated feeder requirement is between 14 and 16 pigs for the growing phase, and between 17 and 18 pigs for the finishing phase.