EVERYDAY PLANNING · VERSION 1.0.0

Chord & Sagitta Calculator

Find a circle’s radius from chord width and arc rise.

Instant calculationCompare five scenariosJSON + CSV exports

Your inputs

Calculation results

Formula & assumptions

Radius = c²/(8s)+s/2.

Values use the specified units. Calculations use floating-point arithmetic. Check input measurements and formula assumptions before applying the result.

Compare your scenarios

Save up to five results to compare changes side by side. Scenarios stay in this tab until you clear or reload it.

Using Chord & Sagitta Calculator

Find a circle’s radius from chord width and arc rise.

Enter chord width, sagitta rise using the units printed under each field.
Choose Calculate, or enable live updates. Review the result labels and formula assumptions.
Save scenarios to compare up to five variations, then copy the report or download JSON or CSV.

Example

Chord width: 20 cm
Sagitta rise: 3 cm
Radius · cm: 18.166667
Diameter · cm: 36.333333

Questions & answers

What does Chord & Sagitta Calculator calculate?

Find a circle’s radius from chord width and arc rise.

Which units should I enter?

Chord width uses cm. Sagitta rise uses cm. Convert values to these units before calculating.

Which formula does it use?

Radius = c²/(8s)+s/2.

What does the included example show?

Chord width: 20 cm; Sagitta rise: 3 cm. Result: Radius · cm = 18.166667; Diameter · cm = 36.333333.

Can I compare different settings?

Yes. Save a scenario, change the inputs and save another result. Up to five scenarios are compared in this tab; they disappear when you reload or leave.

Can I export the calculation?

Copy the JSON report or download JSON and CSV with inputs, result labels and numeric values. Processing uses local JavaScript; no calculation request is sent to our server. Displayed values use up to 10 significant digits; exports retain JavaScript numeric precision.