Both self-propelled and push lawn mowers require the operator to walk behind the lawn mower and hold onto the handles. However, a push lawnmower requires that the operator exert physical force on the mower, while the self-propelled lawn mower moves on its own. Make your decision whether to buy a self-propelled mower or a push mower based on your budget, your lawn's size and slope, and your own physical capabilities--or those of whomever is going to be doing the mowing.
Very big lawns usually require self-propelled lawn mowers, since push lawn mowers will take longer and require more stamina. Self-propelled lawn mowers tend to go faster. However, these self-propelled lawn mowers are more likely to accidentally run over flower beds and can also crash into trees if you're not handy with their controls. Still, self-propelled mowers are usually preferable unless a lawn is very small.
Push mowers are usually not as good for mowing grass on steep inclines and declines, since the push mowers are harder to move on those inclines and an operator could lose balance while working on the slope. But there could be a slightly greater risk of a self-propelled lawn mower tilting over on a significant or bumpy slope if the mower is moving faster than topographic conditions allow.
Self-propelled mowers are heavier than push mowers. The greater weight can make a self-propelled mower more difficult to transport if need be. Self-propelled mowers are also larger, requiring more space to store them. Push mowers are often smaller and are easier to maneuver close to areas that self-propelled lawn mowers can't reach, such as nearby trees. However, the size difference is minimal.
Push mowers tend to be cheaper than self-propelled lawn mowers. According to both Clean Air Gardening and Consumer Search, as of 2010, self-propelled lawn mowers tend to cost between $200 and $800, while push lawn mowers range from $119 to $400. As with most products, the quality generally determines the price in the ultracompetitive consumer mower market. Self-propelled mowers are also more likely to break because they are more complex than push mowers.
Push mowers provide a greater workout than self-propelled lawn mowers since those operating push mowers have to put some physical force on the mower in order to get it to move forward. However, those with physical difficulties might not be able to handle a push mower.
Self-propelled mowers tend to have more features than push mowers have and also have stronger engines, which allow the blades on the mower to spin more quickly, cutting the grass more effectively. One feature that some self-propelled mowers have is mulching, which turns grass clippings into compost. These grass clippings provide additional nutrients to the soil so that the landscaper does not have to add as much fertilizer, which saves money. However, you should mulch only once in awhile.