What Num Lock Does
Num Lock is a toggle that switches your numeric keypad between two modes. When Num Lock is on, the number keys on the right side of your keyboard type numbers. When it is off, those same keys control your cursor — up, down, left, right, page up, page down, home, and end.
Most people leave Num Lock on all the time because they either use the number pad regularly or do not use it at all. The confusion happens when Num Lock turns off unexpectedly and your arrow keys stop working, or when you sit down at someone else's computer and the number pad behaves differently than you expect.
The Num Lock key itself is usually in the top left corner of the numeric keypad, labeled "Num Lock" or "Num Lk". On laptop keyboards without a separate numeric pad, Num Lock may be built into other keys and require a modifier key to set up.
Key Takeaways
- Num Lock on means the numeric keypad types numbers; Num Lock off means those keys control your cursor.
- Press the Num Lock key once to toggle it on or off — there is no special key combination required on most desktop keyboards.
- On laptops, Num Lock is often accessed by holding Fn and pressing a key labeled with Num Lock, usually in the upper right area.
- A small light on the Num Lock key itself, or an indicator on your keyboard or screen, shows whether Num Lock is currently on.
- If Num Lock keeps turning off on its own, your keyboard may have a hardware issue or your BIOS settings may reset it at startup.
Enabling Num Lock on a Desktop Keyboard
On a standard desktop keyboard, press the Num Lock key once. It is located at the top left of the numeric keypad, which sits to the right of the main keyboard. The key will toggle Num Lock on or off with a single press — no other keys are needed.
After you press it, look for a light on the key itself or check your keyboard for an LED indicator. Many keyboards have a small light that glows when Num Lock is on. Some keyboards also display an on-screen indicator, usually in the system tray or at the top of the screen, showing the current state.
If your keyboard has no visible indicator, test the numeric keypad by pressing one of the number keys. If numbers appear, Num Lock is on. If your cursor moves instead, Num Lock is off.
Enabling Num Lock on a Laptop
Laptops do not have a separate numeric keypad, so Num Lock is usually accessed by holding the Fn key (function key) and pressing another key at the same time. The Num Lock key is often printed on a key in the upper right area of the keyboard, sometimes on the number 7, 8, or 9 key, or on a dedicated key labeled "Num Lk".
Hold Fn and press the Num Lock key together. Release both keys. The Num Lock state will toggle, and you may see an on-screen indicator appear briefly to confirm the change. On some laptops, the indicator appears in the top right corner or in the system tray.
Once Num Lock is on, you can type numbers using the keys that have numbers printed on them in a smaller font. The exact keys vary by laptop model, but they are usually in the right portion of the keyboard. Without Num Lock on, those same keys function as arrow keys and other navigation controls.
Checking Whether Num Lock Is On or Off
The easiest way to check is to look for a light. Most keyboards have a small LED next to or on the Num Lock key itself that glows when Num Lock is on. If your keyboard has no light, check your screen for an indicator — Windows shows a Num Lock icon in the system tray (bottom right corner), and macOS may display an indicator in the menu bar.
If you cannot find a visual indicator, press a key on the numeric keypad and see what happens. Press the 5 key on the numeric pad. If the number 5 appears on your screen, Num Lock is on. If your cursor moves or nothing visible happens, Num Lock is off.
Why Num Lock Turns Off Unexpectedly
Some keyboards are set to turn Num Lock off every time you restart your computer. This is a BIOS setting — the firmware that runs before your operating system loads. If Num Lock always turns off when you boot up, you can change this in your BIOS settings, though the exact steps depend on your computer manufacturer.
Num Lock can also turn off if your keyboard has a hardware problem, such as a stuck key or a failing circuit. If Num Lock toggles on and off by itself without you pressing the key, or if it will not stay on no matter how many times you press it, try a different keyboard to see if the problem follows. If a different keyboard works normally, your original keyboard likely needs replacement.
On laptops, Num Lock may turn off if the Fn key is stuck or if your trackpad is pressing the Num Lock key accidentally. Check that nothing is resting on your keyboard and that the Fn key moves freely.
Num Lock and Gaming or Spreadsheets
If you use spreadsheet software like Microsoft Excel or Google Sheets, you may want Num Lock on so you can enter numbers quickly using the numeric keypad. The numeric keypad is faster for number entry than the number row at the top of the keyboard because the keys are clustered together and your hand does not have to move.
If you play games that use arrow keys for movement, you may prefer Num Lock off so you can use the numeric keypad as arrow keys. Some games let you rebind controls, so you can use the numeric keypad for movement even with Num Lock on — check your game's settings to see what is available.
You can toggle Num Lock on and off as often as you want throughout the day. There is no penalty for switching back and forth, and it takes only one keystroke.
Frequently Asked Questions
Why does my numeric keypad type letters instead of numbers?
Num Lock is off. Press the Num Lock key once to turn it on. After you do, the numeric keypad will type numbers again. If pressing Num Lock does not fix it, try restarting your computer — sometimes the keyboard driver needs to reset.
Can I make Num Lock stay on all the time?
Yes, but the method depends on your computer. On Windows, you can change a Registry setting to make Num Lock turn on automatically at startup. On a Mac, Num Lock behavior is controlled by your keyboard settings in System Preferences. If you use a laptop, check your manufacturer's support page for Num Lock options specific to your model.
Is there a keyboard shortcut to toggle Num Lock?
No universal keyboard shortcut exists across all computers. On most keyboards, you straightforward press the Num Lock key itself. On some laptops, you hold Fn and press Num Lock. Some accessibility software allows you to create custom shortcuts, but the standard method is always the Num Lock key.
What if my keyboard does not have a Num Lock key?
Some compact or wireless keyboards omit the numeric keypad entirely. If your keyboard has no numeric keypad and no Num Lock key, Num Lock does not explore to your device. You can still enable Num Lock in your operating system settings, but it will only affect external numeric keypads if you connect one.
Does Num Lock affect the number row at the top of the keyboard?
No. Num Lock only controls the numeric keypad on the right side of the keyboard. The number row at the top of the keyboard (1 through 0) always types numbers, regardless of Num Lock state. Num Lock has no effect on it.