Electrical Calculators
Reference tools for wire sizing, voltage drop, conduit fill, ampacity, and service-load checks when you need a quick number before opening the code book.
100%
Free to Use
6
Calculators
Reference tools for wire sizing, voltage drop, conduit fill, ampacity, and service-load checks when you need a quick number before opening the code book.
Calculate voltage drop on long runs and compare the result to common 3% and 5% design guidance values.
Verify NEC 40% fill rule for 1-2 conductors and 31-40% for 3+ conductors. Prevents overloading and damage.
Reference AWG sizes from #14 to 2000 MCM with ampacity ratings and physical dimensions for all conductor types.
NEC-based ampacity ratings accounting for insulation type, temperature conditions, and conductor grouping.
Cross-sectional areas and fill capacities for rigid, intermediate, and flexible conduit types.
Estimate service entrance size for residential, commercial, and industrial applications per NEC requirements.
These pages are for the checks electricians and estimators make all the time: whether a run is getting too long, whether the conduit is crowded, whether the conductor size still makes sense after ampacity and voltage-drop are considered, and whether a rough service estimate is in the right range.
The tools are useful before quoting, ordering material, or laying out a run. They save time when you want a quick answer without doing every step by hand.
They do not replace the actual NEC tables, local amendments, equipment listings, or the final method required for the specific job. Terminal ratings, conductor type, ambient temperature, bundling, and occupancy rules still have to be checked against the live code path.
Use these calculators to narrow the decision, catch obvious mismatches, and speed up early planning. Then verify the final selection against the code section, manufacturer data, and field conditions you are working with.
