Design an Arch

2-Centered Gothic arch or
1-Center Roman or Segmental (flatter) Arch

Produce Detailed Measurements to Build
the Pieces of an Arch Based on Your Input

Print this page

Use the sliders to input information about your design criteria and physical space and get detailed measurements for all the pieces of your arch.

Use a photograph as background and get instant feedback on how your design will look on site.

Use any kind of material for your arch – Stone, brick, wood, tile, etc. Even paint a realistic arch on a wall!

For stone masons, bricklayers, carpenters, designers, crafters, painters, hobbyists - Whatever your craft.

An improperly designed arch, like many other badly designed objects, just looks wrong to the eye. A properly designed arch both pleases the eye and can carry a heavy load without breaking.

Caveat: While this application will provide the factors necessary to accurately design a traditional arch shape, a true load bearing arch needs to be carefully constructed, taking into account many other factors, such as foundation design, strength of the material used to build the arch, overburden, static and dynamic loads, and professional construction techniques.

Although this page will fully comply with your input, consider that:
1. The tallest common Gothic arch's radius is no more than twice the span of the arch.
2. To prevent failure, a segmental arch must have a rise (height above springline) that is equal to at least one-eighth the width of the span. Segmental arches with a rise that is less than one-eighth of the span width must have a permanent support or frame beneath the arch to prevent failure.
EXCEPTION: The thickness of a flat arch must itself encompass a stable arch (for a given width, thickness must be at least width divided by 8).

Javascript must be turned on in your browser.

There are memory leaks to be fixed. Reload the page if it slows down.

Works with:
Comodo Dragon

Identified Problems:

Safari: Photo does not import,
Firefox version 66.03: Will crash on photo import,
MS Edge version 44.17763.1.0: Will crash on photo import,
Internet Explorer version 11: Multiple problems.

If you find additional compatible browsers, or wish to suggest improvements, email:

Enter the actual inside width of the base of your arch to obtain
accurate measurements for construction:

Choose your arch's colors:

(Less than 2 megabytes in size improves performance)
Drag the first set of sliders to set the size of the background image,
and the decimal accuracy of numbers.
Drag the next set of sliders to move your arch.
Drag the next set of sliders to set basic dimensions for your arch.
Mortar Joint:
; Cannot draw an arch, your browser does not support HTML5 Canvas.