Tools · Field Calculators
Electrical Tools
Practical, NEC-based calculators from a contractor that self-performs the work. Free to use — no sign-up, and nothing is stored. Pick a calculator to get started.
Free Calculators
Built by people who pull the wire
Quick estimates for the field and the takeoff. Each tool shows its method and the code reference it’s based on. For design and permit documents, rely on a stamped engineering calculation — our engineering team runs the full studies.
Electrical How-To Guides →
Step-by-step field guides written by our crews — transformers, bonding, conduit, motor controls, and more, with NEC references.
ConductorsVoltage Drop Calculator →
Copper or aluminum, 14 AWG to 1000 kcmil. Single- or three-phase, any voltage, length, and current — with NEC 3% / 5% recommendation flags.
RacewayConduit Fill Calculator →
THHN/THWN-2 in EMT, IMC, Rigid, or PVC, checked against NEC Chapter 9 (53/31/40%) — plus the smallest conduit that fits.
AmpacityWire Ampacity Calculator →
NEC Table 310.16 ampacity for copper and aluminum, with ambient-temperature correction and conductor-bundling adjustment.
BoxesBox Fill Calculator →
NEC 314.16 box volume from conductors, devices, clamps, and grounds — compared to your box’s cubic-inch capacity.
TransformersTransformer Sizing →
Step-down/step-up kVA & full-load amps with NEC 450.3(B) overcurrent protection, buck-boost sizing, and 12/24 V control transformers.
LandscapeLandscape Lighting →
Size the 12V transformer, wire gauge, and tap (12–22V) for low-voltage landscape lighting — path, spot, and in-ground lights, with voltage-drop and loop warnings.
Service SizingResidential Load Calculator →
Whole-house load and service size by the NEC 220.82 optional method — a free educational tool (we’re a commercial contractor).
PanelsPanel Schedule →
Build a printable panel schedule — main breaker or main lug, any size and spaces, with breaker, poles, and description per circuit. Print or save as PDF.
NEC & Fire CodeCode Assistant →
Ask NEC and fire-code questions and get plain-language answers with section citations and worked examples. NEC 2017/2020/2023 — verify with your AHJ.
Tucson Electric PowerTEP Standards →
TEP service requirements, meter/grounding guidance, and an AI assistant grounded in TEP's published guidance — built for local contractors.
Built in Tucson
Free calculators from a Tucson commercial electrician
These tools are built and maintained by Arizona Electrical Solutions — a licensed commercial electrician in Tucson, Arizona and a design-build electrical contractor that self-performs the work. We pull the wire, set the gear, and stand behind it, so every calculator reflects how the NEC actually gets applied in the field on commercial and industrial projects.
If you searched for an electrician in Tucson and landed here, here is who we are: a commercial, industrial, institutional, and municipal contractor working across Tucson, Marana, Oro Valley, Sahuarita, Vail, and Green Valley — and statewide, including Phoenix. We coordinate directly with Tucson Electric Power (TEP) and Trico on metering and the point of connection, account for Tucson’s high ambient temperatures in conductor sizing, and design for monsoon-season surges and dust.
As a design-build electrician, we keep engineering in-house: load calcs, one-lines, photometrics, arc-flash and coordination studies, and permit-ready documents all live under one contract with the install — fewer hand-offs, one accountable team. The free calculators here are planning aids; for stamped design, our engineering team runs the full studies, and our crews build it.
Who builds these electrical calculators?
Arizona Electrical Solutions, a commercial electrician and design-build contractor based in Tucson, Arizona (ROC CR-11 #276948, KB-1 #329360). We build them the way we apply the NEC on real commercial jobs.
What does a commercial electrician in Tucson do?
Commercial electrical work covers service and distribution, switchgear and panelboards, lighting and controls, life-safety and fire alarm, and special systems for offices, retail, warehouses, healthcare, and public facilities — plus the TEP/Trico coordination to energize the building. See our commercial electrician services in Tucson.
What is a design-build electrician?
A design-build electrician handles both the electrical engineering and the installation under one contract, instead of designing to someone else’s plans. The owner gets one estimate, one schedule, and one point of accountability. See our design-build approach.
Are the calculators free, and is anything stored?
Yes, every tool is free with no sign-up, and nothing you enter is stored — the math runs in your browser.
Need a commercial electrician in Tucson?
We engineer, build, and self-perform commercial electrical across Tucson and Arizona — design-build, under one contract.
Request a Bid