# Measuring and setting exact distance between two objects

I need an exact distance of $$0.045$$ meters between the edges of two objects as seen here:

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I can't figure out for the life of me how to:

1. Set the measurement tool's ruler to an exact length of $$0.045$$ meters, as it insists on literally any value above or below.
2. Snap the selected rectangle on the left to an exact distance of $$0.045$$ meters from the edge of the other object.

EDIT: While I've now figured out how to snap edges (make sure Affect>Move is enabled under the Snapping menu), entering the move distance as 0.045 meters from the edge manually winds up with the distance being 0.049244 meters instead:

The ruler on the y axis is also supposed to be 0.03 meters (I'd since tried to move both rectangles again, hence the odd placement).

Turns out, however, I was grabbing the wrong edge! I was selecting top edge of the prism, and not the bottom, which lead to the discrepancy. Since I was in top-down view I didn't notice.

In order to select the bottom edge for measurement, you have to click slightly away from the edge, like so:

Thanks to Harry for helping with this!

FULL SOLUTION: Okay, so Harry's answer allowed me to align the edges of the two objects.

In an attempt to make it more clear for other complete beginners like myself:

1. Enable snapping by clicking the snapping magnet button

1. Click the snapping mode button, set it to "Edge", and make sure "Affect>Move" is enabled. (I'm not sure if the "Snap With" setting is important in this case).

1. Select your object by clicking it using the select box tool.

2. Press G to move your object, and get your cursor to the edge of the other object you wish to align your select object to. Left-click to snap it to the edge.

1. With the right object selected, press G, then press the letter corresponding to the axis you need to move the object (X, Y, or Z). Then, type the exact distance you want. In my case, it's -0.045, for 0.045 meters of distance between the two edges. The - key is used for negative values.

2. When measuring to verify the correct distance was entered and accepted, make sure you select the right edge. See this image to understand why:

Very confusing if you're in 2D mode and don't understand why everything is slightly off.

To select and measure the bottom edge, click slightly away from the edge, like so:

• Just snap one edge to the other, then move it again with G, press X, Y or Z depending on in which direction you want to go, then enter .045 and press Return or LMB (or -.045 if you want to go in the opposite direction). Aug 11, 2022 at 6:41

With the Measure Tool active, hover your mouse over the first edge and then press and hold down Ctrl (which will display a small white circle snapping to the edge) and move along that edge then click LMB to confirm. This creates a 0m measurement annotation. Click LMB this annotation and drag it to the other edge while again holding down Ctrl. Notice how it snaps when it is horizontally aligned.