Set Out a Large Arc in a Confined Space with No Access to Circle Center
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 layout 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.


Height
Radius
Sweep Angle °
Arc Area ft²
Length around Arc
Full Circle Circumference
Full Circle Area ft²

Inside Arc (right side bottom of diagram)
Markout
Outside Arc (left side top of diagram)
Markout
To lay out a large radius arc in a confined area, enter either the maximum height of the arc (above center 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 center 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.
Calculate Arc Height and Width From Radius and Sweep Angle

If you know the Radius of your arc, and the Sweep Angle, and need to find the Height and Width to draw the template, enter Radius and Sweep Angle and hit
Calculate Height to calculate the height and width of the arc. Enter the Height and Width (Chord) above to draw the arc template.

If you're cutting concrete, stone or
ANYTHING and there's
DUST  DON'T TAKE THE RISK
Don't cut it, or cut it wet so there's
NO DUST 
Silicosis Sucks
What do we think?  They're 2 different things:
A
Meter is a device to measure things  like a Volt Meter or a Parking Meter
A
Metre is about 3'3~3/8"
Although diameter and perimeter as measurements  don't seem to fit very well
If the US ever goes Metric, you'll be able to use a Meter to measure Meters  A Meter Meter
All Imperial inputs and dimensions are actual physical finished sizes (unless otherwise noted)
All Metric Inputs in Millimetres (unless otherwise noted)