Everyday Tools

Circle Chord Length Calculator

Estimate chord length from a circle radius and central angle.

Updated April 15, 2026
Free online tool
Planning and research use

Why this page exists

Circle geometry gets easier to work with when radius and central angle turn into a straight-line chord length instead of needing manual trig each time. This calculator helps visitors estimate the length of a circle chord from radius and central angle in degrees.

Interactive tool

Run the estimate

Enter your numbers and read the result first, then use the sections below to understand what affects the outcome.

Calculator

Circle chord length calculator

Estimate chord length from a circle radius and central angle.

Result

8.000000

Estimated chord length using twice the radius times the sine of half the central angle.

Chord length8.000000

Radius used8.000000

Angle used60.000000°

Half-angle used30.000000°

A radius of 8.000000 with a central angle of 60.000000 degrees gives a chord length near 8.000000.
The chord is the straight-line distance between the two points on the circle, unlike arc length which follows the curve.
Use the result whenever you need the straight span across the circle segment instead of the curved distance along the arc.

This is a standard geometry estimate. The formula assumes a normal circle and a central angle measured in degrees from 0 to 360.

Planning note

Last updated April 15, 2026. Use this tool to compare scenarios and plan ahead, then confirm important details with the lender, employer, insurer, contractor, or other qualified provider involved in the final decision.

How it works

What the calculator is doing

Enter a radius and a central angle in degrees.

The calculator converts the angle into the half-angle needed for the chord formula.

It uses standard chord-length math to estimate the straight-line distance between the two points on the circle.

Understanding your result

This is a standard geometry estimate. The result assumes a normal circle and a central angle from 0 to 360 degrees.

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Examples

Ways people use this tool

Example scenarios help turn a quick estimate into a more useful comparison or planning step.

Find the straight span across a circle segment

Chord length is useful when you need the straight-line width instead of the curved distance along the arc.

Compare chord length with arc-based tools

Running the same radius and angle through chord, arc-length, or sector-area tools can make the geometry easier to picture.

Use it in layout or drafting work

A quick chord estimate can help with circle-based sketches, fabrication layouts, and geometry homework.

FAQ

Common questions

How is chord length calculated here?

The calculator uses the standard formula chord length equals twice the radius times the sine of half the central angle.

How is chord length different from arc length?

Chord length is the straight-line distance between two points on the circle, while arc length is the curved distance along the circle between those points.

Why is the central angle entered in degrees?

Degrees are usually the most familiar input for this type of circle problem, so the calculator converts the degree value internally for the trig step.

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Keep comparing

Use these related tools to compare nearby scenarios, check a second estimate, or keep narrowing down the right decision.

Everyday ToolsUpdated April 14, 2026