The Meter — Electrical Calc

The Meter is a calculator for working electricians. Voltage drop, conduit fill and ampacity derating, computed live as you type, on a phone that does not need a signal.

One-time purchase. No ads. No subscription. No tracking. Works completely offline.

THE ANSWER BEFORE YOU FINISH TYPING
There is no Calculate button. The readout sits in your thumb zone and updates on every keystroke, so you can watch the number move as you change a length or a conductor size. Get the answer, or find the size that gets you the answer, without tapping anything.

SHOWS ITS WORKING
Tap the readout and it expands to show the formula, your own numbers substituted into it, and the arithmetic. Check a doubtful result by hand. Defend it to an inspector. Copy it as plain text into an email.

WORKS THE WAY YOU DO
US mode gives you AWG and circular mils, feet, and a conductor material picker. European mode gives you mm² cross-sections, metres, and R and X per km entered straight off the cable data sheet. Switch region once in Settings and every field follows. Type a comma or a point for decimals — both always work.

VOLTAGE DROP
Volts and percentage against a limit you set. Single and three phase. The resistance-constant method in US mode, the impedance method in European mode. Over your limit, it tells you what the next conductor size up would give you.

CONDUIT FILL
Build the run one conductor row at a time, each with its own quantity, so four identical wires is one row and not four. Running total as you go. Over the allowance, it tells you the smallest internal diameter that would fit.

AMPACITY DERATING
Enter the base ampacity and ambient correction factor from the code book you work to. The app applies the conductor-count adjustment and shows you the adjusted figure against your actual load, with the headroom or the shortfall spelled out.

FILED UNDER THE JOB
Save a run with one tap. It files itself under the job you last used, so you are not typing a filename on a ladder. Every saved calculation keeps the units it was made in — a US calculation stays in feet forever, and nothing is converted behind your back. Re-open, edit, or send as plain text.

BUILT FOR SITE CONDITIONS
Every target is a full-width row sized for gloved thumbs. Body text is large enough to read in bad light, and the whole layout survives your phone's largest accessibility text size without clipping. Verdicts are a colour and a word and a needle position, so they still read on a smeared screen or to a colour-blind eye. Light and dark themes, following your system or set by hand.

WHAT IT IS NOT
This app is an estimation and training aid. It computes from standard formulas using values you supply. It contains no code tables and has no knowledge of your installation, your supply, or your local amendments. Results must be verified against the electrical code adopted in your jurisdiction. It is not a substitute for a qualified electrician or engineer.

Not affiliated with, endorsed by, or connected to NFPA, NEN, IEC, or any standards body. No code tables are reproduced in this app.

PRIVACY
The Meter collects nothing and sends nothing. On Android it ships without the internet permission at all — not unused, absent from the manifest. Your jobs stay on your phone.

From MASS Soft.