Conduit Fill Calculator
e.g. 21 mm
Adjust for local rules
e.g. 5.2 mm
e.g. 3
Fill %
38.5%
Max Cables
7
Conduit Area
346 mm²
Status
OK
21 mm conduit, 3 × 5.2 mm cables → 38.5 % fill. Max 7 cables at 40 % limit.
Global Conduit Fill Calculator: Fill % = (cable area × count) ÷ conduit area × 100. Most electrical codes allow **40 %** maximum fill for more than one cable. Adjust the “Max Fill %” field for your local regulation. Add a safety margin for bends/pulling.