Electrical Calculator - Wiring

ElectroCalc draws the circuit while you calculate. Every tool shows a live diagram with your own numbers on it: the cable run coloured by voltage drop, the star or delta connection with its phasors, the resistor network with the current in every branch, the power triangle before and after correction. Change a value and the drawing, the result and the check all update at once.

Built for electricians, maintenance technicians, engineers and students. Works fully offline, no account.

60 TOOLS IN 9 CATEGORIES
• Basics: Ohm's law and power (any two of V, I, R, P), series, parallel and series-parallel networks, voltage and current dividers, Wheatstone bridge, star-delta, energy cost
• AC circuits: single and three-phase power, power triangle, RLC series and parallel, resonance, RC/RL time constant, reactance, neutral current, peak and RMS
• Cables: voltage drop (drop, maximum length or smallest cable), cable size, cable size with derating, conductor resistance
• Protection: breaker and fuse selection, short-circuit current, earth fault loop Zs, RCD/GFCI choice, protective conductor size, earth rod, single-line diagram with the fault level at every board
• Motors: full-load current, speed and slip, starting current, contactor and overload sizing, single-phase motor capacitor
• Transformers and power factor: currents and ratio, power factor correction in kvar and µF per phase with the next standard bank, transformer fault current and losses
• Installation: conduit and box fill, demand load, lighting, battery runtime and banks, solar, EV charging
• Electronics: resistor colour code, SMD and capacitor codes, LED resistor, LM317, 555 timer, RC filter, capacitor networks
• Reference: unit converter, AWG to mm², wire colours by country, IEC and ANSI symbols, IP codes

SOLVE FOR ANY VALUE
Pick what you want to find. Voltage drop gives the drop, the longest run for your limit, or the smallest cable that passes. Ohm's law takes any two values.

IEC AND NEC
Switch between IEC (230/400 V, 50 Hz, mm²) and NEC (120/208/240/480 V, 60 Hz, AWG and kcmil). Every field lets you choose its unit: W, kW or HP; m or ft; °C or °F.

SEE THE WORKING
Show working lists each step with your numbers in the formula, and the table row used, so you can check the result instead of trusting it.

PROJECTS AND REPORTS
Save calculations into projects for a site or customer, compare scenarios side by side, and export a PDF report with the diagrams.

FREE AND PRO
Most tools are free, with diagrams and working included. Free projects hold up to 50 calculations.
ElectroCalc Pro is one payment, not a subscription: protection and fault tools, derated cable sizing, advanced motor and transformer tools, unlimited projects, PDF reports with your company name and logo, CSV, scenario comparison and no ads. Pro works offline and restores on a new phone signed in to the same Google account.

Free users see one small banner on the tool lists. No full-screen ads, and never an ad on a calculation screen.

This is an estimating and learning tool, not certified electrical design. Final cable and protection choices must follow local regulations and be checked by a qualified person.

Privacy: https://bekservice.uk/electrocalc/privacy/
Support: support@bekservice.uk

Recent changes:
ElectroCalc 2: live circuit diagrams on every tool, 60 calculators, IEC and NEC modes, solve for any value, projects and PDF reports.