# cpulimit > A tool to throttle the CPU usage of other processes. > More information: . - Limit an existing process with PID 1234 to only use 25% of the CPU: `cpulimit {{[-p|--pid]}} {{1234}} {{[-l|--limit]}} {{25%}}` - Limit an existing program by its executable name: `cpulimit {{[-e|--exe]}} {{program}} {{[-l|--limit]}} {{25}}` - Launch a given program and limit it to only use 50% of the CPU: `cpulimit {{[-l|--limit]}} {{50}} -- {{program argument1 argument2 ...}}` - Launch a program, limit its CPU usage to 50% and run cpulimit in the background: `cpulimit {{[-l|--limit]}} {{50}} {{[-b|--background]}} -- {{program}}` - Kill its process if the program's CPU usage goes over 50%: `cpulimit {{[-l|--limit]}} 50 {{[-k|--kill]}} -- {{program}}` - Throttle both it and its child processes so that none go about 25% CPU: `cpulimit {{[-l|--limit]}} {{25}} {{[-m|--monitor-forks]}} -- {{program}}`