If you're laying out a large radius arc in a confined area and can't reach the center of the circle, enter arc dimensions below to find lay-out points in the curve.
Also see Printable Arc Templates to create printable paper templates for smaller arcs.
Left click, release and drag to measure at scale in diagram.
Sweep Angle °
Arc Area ft²
Length around Arc
Full Circle Circumference
Full Circle Area ft²
Inside Arc (right side bottom of diagram)
Outside Arc (left side top of diagram)
To lay out a large radius arc in a confined area, enter either the maximum height of the arc (above centre of chord), or the radius of the arc,
and the increments along the chord line for your lay out points.
The smaller the increments, the more accurate (and smooth) the arc line will be.
Mark the base 'chord' line and increments from centre outwards, and measure 90 ° to the arc points to form the arc.
To make sure the measured points are square
off the base line, mark another line parallel to the base line (above or below), square a line through the center, mark corresponding increments and line through
both increment marks to mark the arc points.
To fine tune Slider Controls click to select and use ◄► (cursor) keyboard keys.
Your iPad, iPhone or Android Tablet or Phone is a valuable On-Site tool!
Lay your phone or tablet on an angled surface (roof ?) to directly measure angles and automatically calculate Roofing and Pitch Angle Apps.