Square Up Calculator (3-4-5 Diagonal)
Find the diagonal that makes a layout square, and see how far out of square it is from a measured diagonal. 3-4-5 rule, any size.
- Theoretical diagonal from two legs (Pythagorean theorem)
- Out-of-square amount from a measured diagonal
- Pass/fail against a 1/8" tolerance
How to use
- Enter the two sides of the corner as Side A and Side B. Diagonal is the length that makes the corner exactly 90°.
- Measure the actual diagonal on site and enter it as Measured diagonal. Out of square shows how far it is from the true diagonal; within 1/8" counts as square.
- Angle is the angle between Side B and the diagonal.
- Sides of 3, 4 and 5 units (or 6, 8 and 10) are the classic check for a right angle.
- Length fields accept the same entries as the Feet and Inches Calculator: 9' 6, 7 3/4", 2743mm or 3m + 6'. A plain number means inches, or millimeters when the Units panel is set to metric.
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