pcb_calculator: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/pcb_calculator - from package: kicad

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/pcb_calculator - from package: kicad

You may install the required package with command apt-get install {package}

Error in other languages:
pcb_calculator: bevel nie gevind nie
pcb_calculator: comandă negăsită
pcb_calculator: comando não encontrado
pcb_calculator: commande introuvable
pcb_calculator: command not found
pcb_calculator: käsku ei ole
pcb_calculator: không tìm thấy lệnh
pcb_calculator: komanda nerasta
pcb_calculator: Kommando nicht gefunden.
pcb_calculator: kommandot finns inte
pcb_calculator: komut yok
pcb_calculator: nie znaleziono polecenia
pcb_calculator: níor aimsíodh an t-ordú
pcb_calculator: no se encontró la orden
pcb_calculator: no s'ha trobat l'ordre
pcb_calculator: opdracht niet gevonden
pcb_calculator: parancs nem található
pcb_calculator: perintah tidak ditemukan
pcb_calculator: príkaz nenájdený
pcb_calculator: příkaz nenalezen
pcb_calculator: команда не найдена
pcb_calculator: командата не е открита
pcb_calculator: 命令找不到
pcb_calculator: コマンドが見つかりません