Scope

Box and ring catalogue planning only. It does not perform box-fill calculations or replace the marked volume on the actual box or ring.

Lookup table

Lookup common extension-ring and plaster-ring added volume examples for catalogue comparison.

Scroll sideways to keep row labels aligned with hidden columns.

Lookup basis uses common manufacturer catalogue extension-ring and plaster-ring volume patterns; marked volume governs field application.
Box or ring typeRing depth (in)Added volume (mL)Added volume (in3)Boundary
4 in square0.51237.5catalogue volume planning only; use the marked volume on the actual ring or extension
4 in square124615catalogue volume planning only; use the marked volume on the actual ring or extension
4 in square1.536922.5catalogue volume planning only; use the marked volume on the actual ring or extension
4-11/16 in square0.516410catalogue volume planning only; use the marked volume on the actual ring or extension
4-11/16 in square132820catalogue volume planning only; use the marked volume on the actual ring or extension
4-11/16 in square1.549230catalogue volume planning only; use the marked volume on the actual ring or extension
Notes
  • Check table values for preliminary lookup and arithmetic checks only.
  • Confirm equipment ratings, product markings, installation conditions, utility requirements, and the local authority requirements before design or field use.