Ring Area Calculator
Measure the material area of a flat ring or washer.
Your inputs
Calculation results
Formula & assumptions
Area = π(R² − r²); inner radius must be smaller than outer radius.
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 Ring Area Calculator
Measure the material area of a flat ring or washer.
- Enter outer radius, inner radius 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
Outer radius: 10 cm Inner radius: 6 cm Material area · cm²: 201.06193 Outer circumference · cm: 62.831853 Inner circumference · cm: 37.699112
Questions & answers
What does Ring Area Calculator calculate?
Measure the material area of a flat ring or washer.
Which units should I enter?
Outer radius uses cm. Inner radius uses cm. Convert values to these units before calculating.
Which formula does it use?
Area = π(R² − r²); inner radius must be smaller than outer radius.
What does the included example show?
Outer radius: 10 cm; Inner radius: 6 cm. Result: Material area · cm² = 201.06193; Outer circumference · cm = 62.831853; Inner circumference · cm = 37.699112.
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.
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