Online RulerCalibrate with a bank card
Place a standard bank card flat against the AR Ruler screen and match the calibration guide to the card’s long edge. A nominal ISO ID-1 bank card is 85.60 mm wide along that edge and 53.98 mm high along the short edge. The card gives the ruler a known physical length to work from.
- Match the guide to the long edge, using the two ends of that edge as your reference points.
- The card serves as a physical reference. AR Ruler takes no data from it and uses no upload or sensors for this process.
- The website and desktop or browser extension ruler save the calibration locally.
- Open the card calibration guide on the screen you plan to use for measuring. Set your browser zoom before you start.
- Hold the card flat against the display with its long edge parallel to the guide. Choose an edge you can see clearly without shifting your grip.
- Line up one end of the card with one end of the guide. Adjust the guide until its other end meets the far end of the card.
- Save the calibration, lift the card, and set it back against the guide. Check both ends again before measuring an object.
Use the full edge
Use the full width of the card from one side to the other. On a card with rounded corners, picture where each straight side would meet the long edge if the corner were square. The curved part starts inward from the true end of the width. A line printed on the card may also stop short of the sides. Keep your eyes directly in front of the guide while you adjust it so the card and the marks are easier to compare.
Keep the card flat
Hold the card where you can see both ends. If your fingers cover an end, move your grip toward the middle before making the final adjustment. A tilted card can appear shorter from where you are looking. If the card slides as you adjust the guide, set the starting end back in place and check the far end again. Use light pressure so the card stays flat without bending.
Check after changes
AR Ruler invalidates the saved scale when it detects a browser zoom or display change that affects it. Check the guide with the card after changing zoom, changing display settings, or moving the ruler window to another screen. Do this even if the page still looks familiar. If the guide and card no longer line up, repeat the calibration on the screen you are about to use.
Which edge of the card goes against the guide?
Use either of the two long sides. Both span the nominal width of an ISO ID-1 bank card.
Does the card need to face a certain way?
Either face can rest against the screen. The outer edges give you the reference, so you can keep the printed details covered.
Do I need the card for every measurement?
You can use the locally saved scale for later measurements. Bring the card back out to check the scale after a browser zoom or display change.