Lighting Cable Voltage Drop Calculator
Estimate voltage drop on a long power run from cable cross-section, length and current — so distant fixtures don't dim or colour-shift.
A 13 A load down 50 m of 1.5 mm² cable drops ~8 V (3.5%) — enough to visibly dim tungsten and shift its colour temperature warmer at the far end. Keep volt-drop under ~3–5%; the fix is thicker copper or a shorter run. LED fixtures with switch-mode supplies tolerate more, but data and inrush still care.
Rule / Formula
Note: Estimate using DC resistance of copper; real installations must be verified to local wiring regulations.
Estimate voltage drop on a long power run from cable cross-section, length and current — so distant fixtures don't dim or colour-shift.
About Lighting Cable Voltage Drop Calculator
Estimate voltage drop on a long power run from cable cross-section, length and current — so distant fixtures don't dim or colour-shift. A 13 A load down 50 m of 1.5 mm² cable drops ~8 V (3.5%) — enough to visibly dim tungsten and shift its colour temperature warmer at the far end. Keep volt-drop under ~3–5%; the fix is thicker copper or a shorter run. LED fixtures with switch-mode supplies tolerate more, but data and inrush still care.
How to use Lighting Cable Voltage Drop Calculator
- 1Enter your values into the fields in Lighting Cable Voltage Drop Calculator.
- 2The result and any pass/fail verdict update instantly as you type — no button to press.
- 3Check the substituted formula and worked example to see exactly how the result was derived.
- 4Copy or note the result for your spec, delivery or planning.
Why use Lighting Cable Voltage Drop Calculator?
- ✓Runs entirely in your browser with instant, private results — no data leaves your device.
- ✓Built on a published reference: IET/IEC voltage-drop guidance; copper resistivity.
- ✓Shows the governing formula and a worked example, so you can trust and check every result.
- ✓100% free with no sign-up, no watermark and no usage limits.
- ✓Works on any device — desktop, tablet or phone — and keeps working offline once loaded.
Frequently asked questions
What does Lighting Cable Voltage Drop Calculator do?+
Estimate voltage drop on a long power run from cable cross-section, length and current — so distant fixtures don't dim or colour-shift. A 13 A load down 50 m of 1.5 mm² cable drops ~8 V (3.5%) — enough to visibly dim tungsten and shift its colour temperature warmer at the far end.
Is my data private?+
Yes. Lighting Cable Voltage Drop Calculator runs entirely in your browser — your inputs are never uploaded, stored or logged.
What standard or source is Lighting Cable Voltage Drop Calculator based on?+
It follows IET/IEC voltage-drop guidance; copper resistivity. Always confirm against the current official document, as specifications and rates can change.
What formula does it use?+
Lighting Cable Voltage Drop Calculator uses: loop resistance = ρ·(2L)/A (ρ_copper ≈ 0.0175 Ω·mm²/m); drop = current × loop resistance. The tool shows this formula with your own numbers substituted so you can verify the result.
Is Lighting Cable Voltage Drop Calculator free to use?+
Yes — it is completely free with no account, no sign-up and no usage limits. There is no watermark and no paywall.
Embed Lighting Cable Voltage Drop Calculator on your website
Want Lighting Cable Voltage Drop Calculatoron your own site? Paste this snippet into any HTML page — it's free, with no API key or sign-up. The tool loads in an iframe and keeps working exactly as it does here.
<iframe src="https://tooljolt.com/tools/lighting-cable-voltage-drop-calculator" width="100%" height="640" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" title="Lighting Cable Voltage Drop Calculator — ToolJolt" loading="lazy"></iframe>Related Broadcast tools
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