Photoshop has Ruler and the Ruler Tool. Both help with accuracy. The Ruler tool helps you to position elements accurately in the work area. When the rulers are visible, they are usually at the top and left of the work area. The Ruler tool helps you position images and elements precisely. The Ruler tool is located on the left tools panel in the same tools group as the Eyedropper tool, the Color sampler tool, and the Note tool.
How to use the Ruler in Photoshop
The ruler is usually located at the top and left side of the work area. If the ruler is not visible, you can go to the top menu bar and press View then Ruler or press Ctrl + R. both options will toggle the Ruler on and off. Whenever you move the cursor in the work area you will see marks moving on the rulers showing the position of the cursor on the screen. The ruler is accurate and can be used to get the measurement of objects and the distance between objects in the work area. If you click and drag from the ruler to the canvas, you will get guides. The guides along with the ruler can help to align objects on the screen accurately.
Changing a ruler’s zero origin
Changing the ruler’s 0 origin means changing the position where the starting point (0) for measurement on the ruler is. The default zero position of the ruler is usually at the left edge of the document. Note that whenever you open a new document, the default zero origin will return. To reset the zero origin to the default, double-click the upper left corner where the rulers meet.
There are two ways that the zero origin of the ruler can be decided.
- Choose View > Snap To, then choose any combination of options from the submenu.
This snaps the ruler origin to guides, slices, or document bounds. You can also snap to the grid.
- This method of setting the zero origin will require you to put the cursor at the top left of the screen where the rulers meet, you will click and drag the cursor diagonally toward the canvas.
You will see the crosshair and some lines appear as you drag, wherever you stop will be the new zero origin.
Change the unit of measurement
A document you are working on may ask for a specific unit of measurement or you may be more comfortable working with a specific unit of measurement. Whatever the case may be, you would want the option to be able to change the unit of measurement. To change the unit of measurement of the ruler do any of the following:
- Double-click any of the rulers, and the Preferences window with the Units options will appear. Choose the unit of measurement that you want then click Ok to confirm or Cancel to exit without committing changes.
- You can also go to Edit then Preferences then Units and rulers. The Preferences window with the Units options will appear. Choose the unit of measurement that you want then click Ok to confirm or Cancel to exit without committing changes.
- You can also change the unit of measurement from the Info panel. Go to the info panel in the work area. If it is not there go to Window then Info or press F8.
On the top left corner of the info, panel click the menu button and choose Panel options from the menu that appears.
Choose the unit of measurement that you want then click Ok to confirm or Cancel to exit without committing changes.
Note: if you choose Point/Pica Size, choose from the following options:
PostScript (72 points per inch)
Sets a unit size compatible for printing to a PostScript device.
Uses 72.27 points per inch, as traditionally used in printing.
How to use the Ruler Tool in Photoshop
The ruler tool is located on the left tools panel. It is in the same tools group as the Eyedropper tool, the Color sampler tool, and the Note tool. The Ruler tool calculates the distance between any two points in the workspace. When you measure from one point to another, a nonprinting line is drawn, and the options bar and Info panel show the following information:
- The starting location (X and Y)
- The horizontal (W) and vertical (H) distances traveled from the x and y axes
- The angle measured relative to the axis (A)
- The total length traveled (D1)
- The two lengths traveled (D1 and D2) when you use a protractor
All measurements except the angle are calculated in the unit of measure currently set in the Units & Rulers preference dialog box.
If your document has an existing measuring line, selecting the Ruler tool causes it to be displayed.
How to measure between two points
- Select the Ruler tool. (If the Ruler isn’t visible, hold down the Eyedropper tool.)
- Drag from the starting point to the ending point. Hold down the Shift key to constrain the tool to 45° increments.
- To create a protractor from an existing measuring line, Alt-drag at an angle from one end of the measuring line. Hold down the Shift key to constrain the tool to multiples of 45°.
Note: holding the Shift key while you drag has the additional function of ensuring that the line is kept straight.
Edit a measuring line
- To resize the line, drag one end of an existing measuring line.
- To move the line, place the pointer on the line away from either endpoint and drag the line.
- To remove the line, place the pointer on the line away from either endpoint, drag the line out of the image, or click Clear in the tool options bar at the top.
Note: if you drag a measuring line on an image or between two images that are supposed to be horizontal or vertical then go to Image then Image rotation the Arbitrary. The correct angle and the direction of rotation that is required to straighten the line will show. If you click ok then the canvas will rotate at the angle.
How do you show Ruler and Ruler guides in Photoshop?
To use the Ruler tool in Photoshop, simply click and drag your mouse from one point to another. The Ruler tool can be found in the left tools panel. It is used to draw straight lines and measure distances. To use the Ruler tool, click and hold down the left mouse button, then drag the cursor to draw a line.
Is there a Ruler function in Photoshop?
Yes, Photoshop comes with a Ruler tool or function that helps you measure your sheet and draw as you like. To use this tool, you need to press Ctrl+R. Alternatively, you can follow the aforementioned guide to open up the Ruler function and start using this tool in any window.