How to open terminal in Mac using keyboard shortcut? [duplicate]

Press CmdSpace to open spotlight search, and type terminal and hit return.

Or if you are in the terminal press CmdT to open a new tab OR CmdN to open a new Terminal window.

Karabiner-Elements (10.12 and later)

Karabiner stopped working in 10.12 due to changes in the kernel architecture, and Karabiner was rewritten as Karabiner-Elements which uses a new JSON format for the configuration files.

You can now add a rule like this to karabiner.json (https://pqrs.org/osx/karabiner/json.html):

{
  "from": {
    "key_code": "t",
    "modifiers": {
      "mandatory": [
        "right_option"
      ]
    }
  },
  "to": [
    {
      "shell_command": "open -aterminal"
    }
  ],
  "type": "basic"
}

Karabiner (10.11 and earlier)

Save a file like this as private.xml:

<?xml version="1.0"?>
<root>
  <vkopenurldef>
    <name>KeyCode::VK_OPEN_URL_TERMINAL</name>
    <url>file:///Applications/Utilities/Terminal.app</url>
  </vkopenurldef>
  <item>
    <name>custom</name>
    <identifier>custom</identifier>
    <autogen>__KeyToKey__ KeyCode::T, ModifierFlag::OPTION_R | ModifierFlag::NONE, KeyCode::VK_OPEN_URL_TERMINAL</autogen>
  </item>
</root>

Alfred

If you have bought the Powerpack for Alfred, you can create a workflow like this:

Hotkeys have a short delay by default, but you can reduce the delay by changing the "Trigger behaviour" option from "Simulate modifier keys released" to "Pass through modifier keys (Fastest)":

iTerm 2

iTerm 2 has an option to enable a global keyboard shortcut for focusing the application in "Preferences > Keys > Show/hide all windows with a system-wide hotkey":