If you've ever printed a photo and wondered why it looks nothing like it did on screen, or noticed that colours in a presentation look washed out on the meeting room display, the answer is almost always calibration. Learning how to calibrate and measure a monitor is one of the highest-value things you can do for any display-dependent work, from graphic design and photo editing to video calls and coding. It doesn't require expensive equipment for most users, and the difference in accuracy is immediately visible.
What calibration actually means
Calibration adjusts a monitor's output so it matches a known reference standard. The two most common standards are sRGB (the default colour space for web content and Windows) and Display P3 (wider gamut, used in Apple's ecosystem and professional video). Most office monitors target sRGB. A calibrated monitor in sRGB will show colours that match what another calibrated sRGB screen shows, which is why the standard exists.
Measurement is different from calibration. Measuring a monitor means reading its actual output with a colorimeter or spectrophotometer and comparing it to the target. You can measure without calibrating, and calibrating without measuring is guesswork. For serious work, you do both.
Three values matter most:
- White point: the colour temperature of pure white, typically D65 (6500K) for most content and D50 (5000K) for print-matching.
- Gamma: the relationship between input signal and output brightness. The standard for SDR content is 2.2.
- Luminance: peak brightness, usually set to 120 cd/m² for a dim room or up to 200 cd/m² in bright office environments.
What you need to get started
For basic calibration, Windows and macOS both include built-in tools. On Windows, open the Start menu and search for "Colour Calibration". On macOS, go to System Settings, then Displays, then Colour, and click Calibrate. These walk you through visual adjustments to gamma and white point. They're better than nothing but rely on your eye, which is inconsistent.
For accurate results, use a hardware colorimeter. The X-Rite ColorChecker Display is the most widely used consumer option in Australia, and it ships with software that fully automates measurement and profile generation. The Calibrite ColorChecker Display Plus is a step up for HDR panels. These devices run from around AU$180 to AU$400 and are shared easily across a team or fleet.
If you're managing a fleet of business laptops or external monitors, centralising a single colorimeter and scheduling periodic calibration checks is far more cost-effective than buying one per device. For how the display connects to your workstation in the first place, it's worth reviewing how to connect a laptop to a monitor or TV, since the connection type affects signal quality and colour depth.
Step-by-step: how to calibrate a monitor with a colorimeter
Start with the monitor warm. Run it for at least 30 minutes before calibrating, because cold panels drift in colour temperature as they heat up. Close any application that might change screen content automatically, and set your room lighting to whatever it will be during normal use.
Open your calibration software (X-Rite's i1Profiler or the bundled ArgyllCMS-based tools work for most colorimeters). Select your target values: white point D65, gamma 2.2, luminance 120 cd/m² for a typical office. The software will display a series of colour patches while the colorimeter reads them off the screen. This takes 3 to 10 minutes depending on the number of patches.
When the measurement run completes, the software generates an ICC colour profile. On Windows, right-click the profile file and select "Install Profile". Then open Colour Management (search for it in Control Panel) and set the new profile as the default for that display. On macOS, the calibration wizard installs the profile automatically and sets it active immediately.
Recalibrate monthly if colour accuracy matters to your work. Monitors drift as backlights age. A display that was accurate six months ago may now be running warm (too yellow) or cool (too blue) without any visible sign until you measure it.
Measuring a monitor without a colorimeter
Several free web-based tools let you check basic display accuracy visually. Lagom LCD test pages include patterns for checking gamma, contrast, sharpness, and colour gradients. They won't give you numbers, but they'll reveal obvious problems like crushed blacks, blown-out highlights, or banding in gradients.
For sharpness, use a pixel-level grid test at native resolution. If sub-pixel rendering is off or the display is running at a non-native resolution, you'll see fringing immediately. This matters most on external monitors connected via USB-C or DisplayPort, where the resolution negotiation sometimes defaults to a scaled mode. Check your display settings and confirm you're at native resolution before concluding anything is wrong with colour.
Common calibration mistakes and how to avoid them
The most frequent mistake is calibrating the software profile without adjusting the monitor's hardware controls first. The GPU applies the ICC profile as a correction on top of whatever the panel outputs. If the monitor's brightness is set to 100% and the target luminance is 120 cd/m², the profile will push the correction beyond what the display can cleanly handle, introducing banding in dark tones. Set hardware brightness first, confirm it's close to your target luminance with the colorimeter, then let the profile handle the fine correction.
The second mistake is calibrating in a different lighting condition than the one used for normal work. A monitor calibrated under bright fluorescent light and then used in a dim evening environment will appear too cool. Keep ambient light consistent or use a display hood to isolate the screen from ambient variation.
Third: don't forget the second screen. In dual-monitor setups, both displays need their own ICC profiles. A calibrated primary next to an uncalibrated secondary creates jarring colour shifts when you drag windows between them. This is a common complaint in multi-screen laptop setups, and the fix is simply running calibration on each panel separately.
If your setup involves connecting to a projector for presentations, the same principles apply, though projectors drift far more quickly than LCD panels and usually require calibration before each major use. The article on how to connect a laptop to a projector covers the connection side; calibrating the projected image follows the same colorimeter workflow once a stable connection is established.
When to invest in a spectrophotometer instead
A colorimeter measures display output well but is factory-characterised for specific display types. If you're working with an OLED panel, a wide-gamut professional monitor, or a display using quantum dot technology, the characterisation may be less accurate. A spectrophotometer (such as the X-Rite i1Pro 3) measures the full spectral output directly and doesn't depend on factory characterisation. It's also the tool used to build the colorimeter's own calibration data.
For most users, including professional photographers and video editors, a good colorimeter is accurate enough. Spectrophotometers matter when you're in a prepress or broadcast environment where the measurement tool itself needs to be traceable to a physical standard. The price difference is significant: AU$300 for a colorimeter versus AU$2,000 or more for a spectrophotometer. Rent one for an afternoon rather than buying if you only need it occasionally.
Keeping calibration in a team environment
In an IT procurement context, monitor calibration is easy to systematise. Document the target values for your environment (most offices do well with D65, 2.2 gamma, 120 cd/m²). Buy one colorimeter for the team. Schedule calibration every 90 days, or after any monitor replacement. Store the generated ICC profiles in a shared location so they can be deployed via MDM or group policy on Windows devices. macOS profiles can be distributed through configuration profiles in Jamf or similar tools.
For teams with colour-critical workflows, build calibration verification into the hardware refresh cycle. A monitor that can no longer reach target luminance without the profile doing excessive correction is approaching end of useful life for colour work, even if it still looks fine for general use. Measurement data tells you this objectively, well before the visual degradation becomes obvious to users.