How to Make a Half Circle in Adobe Illustrator

Whether you want to create a logo or design infographics, making a shape is one of the first things you will learn how to do with the Adobe Illustrator program. You can make a half-circle in Illustrator using the Knife, Scissors, Ellipse, and the Direct Selection tool.

Hi, my name is Rita. I have been using Adobe Illustrator for over five years. When I started using Adobe Illustrator, I struggled to make a half-circle because I didn’t know what tool to use. 

I still remember using the rectangle to make a clipping mask on a circle to get a half circle, but there are quicker ways. 

In this tutorial, I will show you four quick ways to make a half circle in Illustrator.

Key Takeaways

  • Hold the Shift key while drawing with the Ellipse Tool to make a perfect circle. 
  • Using the Appearance panel and other Illustrator tools to customize your half-circle, you can apply strokes, fills, gradients, or other styling options.
  • When you use the Knife tool, hit the Alt (Option for Mac users) key to create a straight-cut line. 

4 Quick Ways to Make a Semi-Circle in Illustrator

To make a semi or half-circle in Illustrator, you must first create a complete circle. Let’s make a full circle using the Ellipse Tool

Go to the toolbar to select the Ellipse tool, hold the Shift key, click on the artboard, and drag it to make a perfect circle. 

Let’s make a half-circle from the complete circle below.

Have you created your full circle? I bet you have. It’s time to cut the full circle in half using the Knife, Scissors, Ellipse, and Direct Selection Tool.

Note: All screenshots are from Adobe Illustrator CC Windows Version. Mac and other versions may appear different. 

Method 1: Knife Tool

Making a half-circle using the knife tool is easy. Let’s see how this works in practice.

Step 1: Select the circle using the Selection Tool (or keyboard shortcut V). 

You will see the anchor points when you select the circle. The knife tool lets you cut a circle in half through two anchor points.

Since you have four anchor points in a complete circle, you can divide the process from left to right or top to bottom.

Step 2: Select the Knife Tool from the toolbar. 

You should find the knife tool in the same menu as the Eraser Tool. If it’s not there, click the Edit Toolbar from the sidebar.

And you can find the Knife tool from the Edit Toolbar menu.

If you use the knife tool often, click the Edit Toolbar and drag it to the Eraser tool menu for convenience.

Step 3: Use anchor points to draw a dividing line across the circle. Hold the Alt (Option for Mac users) key, then click on one anchor point and drag through the circle to connect the anchor point across from the one you clicked. 

Note: You can drag across from the center from up to down or side to side.

Holding the Alt (Option for window users) key helps you to draw a straight line. 

Note: You need to hold the Alt and Shift keys to cut across the anchor points. Be sure the arrow on the knife tool is on the anchor point instead of the tip of the knife itself. Also, cut through beyond the circle before releasing the cursor. 

Step 4: Select the half-circle. Use the selection tool or press V on your keyboard. You will see that one-half of the circle is selected when you click on the circle.

Depending on your design goals, you can move the half-circles apart, delete one half, or modify them. 

You can make a half circle from a fill or circle stroke. Our circle has both fill and stroke.

Method 2: Scissors Tool

You can also use the Scissors Tool to make a half-circle. The scissors tool works like the knife tool but is slightly different. 

Let’s see how it works in practice.

Step 1: Select the circle. Click on the Selection Tool from the sidebar or strike the letter V on your keyboard. Selecting the shape will help you see the anchor points like we did using the knife tool.

Step 2: Use the scissors tool to click on one of the two anchor points across each other. You’ll notice that your circle is already split in half.

Step 3: Edit the spilt circle. Use the selection tool to see the divided circle. You can make your preferred edits. You can separate, delete, or close the path of your half-circle.

Did you notice that our half circle looks different from the full circle?

That is because our full circle has a stroke outline, but a part of our half circle is missing a stroke.

Let’s close the stroke path of our half circle. 

Step 4: Close the stroke path. The stroke of our half circle is open, so we have to close it. To do that, we’ll go to the overhead menu and then select Object > Path > Join to close/join the path (or the keyboard shortcut Ctrl/Command + J)

Method 3: Direct Selection Tool

Making a half-circle using the direct selection tool is my favorite method. I can make a half circle in seconds with this method. 

Follow these steps to make a half circle using the direct selection tool. 

Step 1: Choose the Direct Selection Tool from the toolbar or use the keyboard shortcut A.

Step 2: Select and delete anchor points. Click on one anchor point and press the Delete button. The anchor point you clicked on will be immediately deleted. 

I clicked on the anchor point at the bottom of the circle to get a half circle cut through from the side. 

Your circle will look like this after deleting one anchor point.

Your half-circle will look like this if you only use a stroke.

Step 3: Close the path if this is different from the effect you want to achieve. Use the keyboard shortcut Ctrl/Command + J to do so. 

Method 4: Ellipse Tool 

Can we use the ellipse tool to make a half-circle? Yes, we can. We can use the ellipse tool to create a full and a half circle. 

Let’s see how this works in practice.

Step 1: Create a complete circle using the Ellipse Tool

Step 2: Use the small handle around the bounding box to form a half-circle. Do this by dragging around the handle to create a pie graph. 

You can drag the handle in your preferred direction to make a half-circle. 

You can use this method to make a pie chart or cut your circle into small parts.

Final Thoughts

You can use the four methods above to make a half circle in Illustrator. I prefer the Direct Selection Tool method to make a half circle. The Ellipse tool method is the most challenging for me because getting a perfect 180-degree half-circle is pretty tricky. 

For example, when you drag through the circle, you must hold the Shift + Alt key (for Windows) and the Option key (for Mac users). It ensures you get a perfect straight line when using the Knife tool.

Which method do you like best? Let us know in the comment section below.

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