Lighting Dimmer / Circuit Load Calculator
Check how many fixtures fit on a dimmer or circuit: enter fixture wattage, count and circuit rating to get load, current and the 80% safe limit.
Three 575 W fixtures on a 230 V circuit draw ~7.5 A — comfortable on a 16 A circuit, whose continuous-load safe limit (80%) is 12.8 A. Lighting is a continuous load, so the 80% rule applies: size circuits to it, not the breaker's instantaneous rating, to avoid nuisance trips mid-show.
Rule / Formula
Note: Electrical planning aid only — always have a qualified electrician verify rigging power. Not a substitute for local code compliance.
Check how many fixtures fit on a dimmer or circuit: enter fixture wattage, count and circuit rating to get load, current and the 80% safe limit.
About Lighting Dimmer / Circuit Load Calculator
Check how many fixtures fit on a dimmer or circuit: enter fixture wattage, count and circuit rating to get load, current and the 80% safe limit. Three 575 W fixtures on a 230 V circuit draw ~7.5 A — comfortable on a 16 A circuit, whose continuous-load safe limit (80%) is 12.8 A. Lighting is a continuous load, so the 80% rule applies: size circuits to it, not the breaker's instantaneous rating, to avoid nuisance trips mid-show.
How to use Lighting Dimmer / Circuit Load Calculator
- 1Enter your values into the fields in Lighting Dimmer / Circuit Load 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 Dimmer / Circuit Load Calculator?
- ✓Runs entirely in your browser with instant, private results — no data leaves your device.
- ✓Built on a published reference: NEC 210.20 / IEC continuous-load 80% guidance.
- ✓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 Dimmer / Circuit Load Calculator do?+
Check how many fixtures fit on a dimmer or circuit: enter fixture wattage, count and circuit rating to get load, current and the 80% safe limit. Three 575 W fixtures on a 230 V circuit draw ~7.5 A — comfortable on a 16 A circuit, whose continuous-load safe limit (80%) is 12.8 A.
Is my data private?+
Yes. Lighting Dimmer / Circuit Load Calculator runs entirely in your browser — your inputs are never uploaded, stored or logged.
What standard or source is Lighting Dimmer / Circuit Load Calculator based on?+
It follows NEC 210.20 / IEC continuous-load 80% guidance. Always confirm against the current official document, as specifications and rates can change.
What formula does it use?+
Lighting Dimmer / Circuit Load Calculator uses: current = (watts × fixtures) ÷ voltage; continuous-load safe limit = breaker × 0.8. The tool shows this formula with your own numbers substituted so you can verify the result.
Is Lighting Dimmer / Circuit Load 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 Dimmer / Circuit Load Calculator on your website
Want Lighting Dimmer / Circuit Load 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-dimmer-load-calculator" width="100%" height="640" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" title="Lighting Dimmer / Circuit Load Calculator — ToolJolt" loading="lazy"></iframe>Related Broadcast tools
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