FREE FOREVER · NO SIGN-UP

Size a low-voltage circuit,
free of charge.

Up to 100 kW, one circuit at a time, in the browser. Enter the circuit data and get the cross-section, current capacity, voltage drop, protective device, short circuit and the CEI 64-8 checks — each with its clause. No account, no card.

The calculator opens on app.mantiqi-engineering.com, the ElecCalc platform. Interface in Italian, English and French.

Everything a circuit needs, with the standard alongside.

The same calculation engine as ElecCalc Base, open to anyone for the most common case: a single low-voltage circuit.

Open the free calculator
  1. 01

    Design current

    Single-phase or three-phase, from the power and the power factor.

  2. 02

    Cross-section of the conductors

    Of the live conductors and of the protective conductor.

  3. 03

    Current-carrying capacity

    With the factors for temperature, grouping and installation method.

  4. 04

    Voltage drop

    In volts and per cent, over the actual length.

  5. 05

    Circuit-breaker

    Rating and tripping curve coordinated with the cable.

  6. 06

    Far-end short circuit

    Fault current and the cable's thermal withstand.

  7. 07

    CEI 64-8 checks

    Every check with its result and its clause of the standard.

Three steps, no manual.

01

Open the calculator

From a computer or a phone, on site too. Nothing to install, nothing to register.

02

Enter the circuit data

System, power, length, installation method and cable. The same fields you fill in on a real project.

03

Read the results

Proposed cross-section, coordinated protective device and every check with its CEI 64-8 reference. If something fails, you see why.

What it does and what it doesn't.

Does

One low-voltage circuit at a time, up to 100 kW. Forever, with no expiry and no countdown.

Does

Results with the standard reference: you always know which clause you are checking.

Doesn't

Circuits above 100 kW, networks of boards, medium voltage, take-offs: for those there is ElecCalc Base.

Doesn't

The design in your place. It is a support tool: assumptions, choices and the result remain with the responsible professional.

The same calculation, inside AutoCAD.

ElecCalc Base brings this engine into the drawing: select the block, size it, pick the protective device from 16,000 devices by six manufacturers and save. The drawing becomes the project database, with take-off and report ready.

  • AutoCAD 2019-2027, AutoCAD LT 2024+, ZWCAD 2026
  • 14-day trial, no card
  • From €24.90 a month, or €249 a year
ElecCalc inside AutoCAD: a circuit sized and verified to CEI 64-8, with the protective device selected from the catalogue and the matching RCD Real screenshot of ElecCalc Base in AutoCAD

Before you open the calculator.

Is it really free, or is it a trial?

It is free forever for sizing and verifying a low-voltage circuit up to 100 kW. It does not expire, it does not ask for a card, it does not ask for an account. The 14-day trial is for a different product, ElecCalc Base for AutoCAD.

Do I have to sign up?

No. Open the address and start entering the data.

Can I trust the result?

It is the same calculation engine as ElecCalc Base, and every check quotes the CEI 64-8 clause it applies. It remains a support tool: installation conditions, temperature, upstream protection and special requirements can change the result, and responsibility for the design stays with the professional.

What if the circuit is above 100 kW?

You need ElecCalc Base, which has no such limit and also writes the result into the drawing. You get 14 days of trial with no card to see whether it suits you.

Does it work from a phone?

Yes: it is a web page, it works from any browser, on site too.

Got a circuit to size right now?

One minute, no sign-up, results with the standard clause.

Open the free calculator