iphone locked out

Connect in recovery mode and restore on the computer you usually sync to and you'll get the option to reset the passcode during this process.

See also: iOS: Wrong passcode results in red disabled screen

If you don't have access to a computer

If you are using Find My iPhone, you can use Remote Wipe to restore your device. If you have been using iCloud to back up, you may be able to restore the most recent backup to reset the passcode.

If you have previously synced your device with iTunes

You may be able to reset the passcode by restoring the device.

1. Connect the device to the computer with which you normally sync and open iTunes.
   Note: If iTunes prompts you to enter the passcode, try another computer that you have synced with. Otherwise, go to "If you have never synced your device with iTunes", below.
2. Right-click the device in the left column and select Back up.
3. When the backup is complete, select Restore.
4. When finished, restore from your most recent backup.

If you have never synced your device with iTunes

Connecting the device may result in this error message: "iTunes could not connect to the [device] because it is locked with a passcode. You must enter your passcode on the [device] before it can be used with iTunes."

1. Disconnect the USB cable from the device, but leave the other end of the cable connected to your computer's USB port.
2. Turn off the device: Press and hold the Sleep/Wake button for a few seconds until the red slider appears, then slide the slider. Wait for the device to turn off.
3. While pressing and holding the Home button, reconnect the USB cable to the device. The device should turn on.
4. Continue holding the Home button until you see the "Connect to iTunes" screen. When this screen appears, release the Home button.
5. iTunes should alert you that it has detected a device in recovery mode. Click OK, and then click Restore to restore the device.