Signage, Displays & Architectural Graphics calculator

Power Supply Sizing Calculator

Power Supply Sizing here estimates the operating energy cost of the power supplies driving an illuminated sign or display, and breaks it down to a cost per illuminated unit. Sign designers and facility managers use it to right-size supplies, forecast the electric bill a sign will add, and compare LED retrofits against legacy lighting. Connected load times runtime times rate gives the energy cost; dividing by unit count exposes what each letter, module or panel costs to keep lit. It turns a vague 'the sign draws power' into a number you can put in a proposal or a payback analysis.

What this calculator does

  • Power Supply Sizing here estimates the operating energy cost of the power supplies driving an illuminated sign or display, and breaks it down to a cost per illuminated unit.
  • Use it when power supply sizing in signage, displays and architectural graphics is being quoted and energy is a real chunk of the signage, displays and architectural graphics cost stack.
  • It multiplies connected load by runtime and energy rate to get daily energy cost, then divides by the number of illuminated units for a per-unit cost.

Formula used

  • Energy cost = connected load × runtime × energy rate
  • Power Supply Sizing energy per unit = energy cost ÷ processed units

Inputs explained

  • Connected LED/lighting load:
  • Daily illuminated runtime:
  • Electricity rate:
  • Units illuminated by the supply:

How to use the result

  • Use it when specifying power supplies or estimating the operating electricity cost of an illuminated sign, channel-letter set or display wall.
  • It assumes a single steady load and rate; dimming, driver inefficiency and tiered utility pricing will shift real costs above or below the estimate.

Current U.S. benchmarks

  • As of Apr 2026, industrial electricity averages 8.7 cents per kWh across the U.S. (EIA), up 5.5% from a year earlier. State averages range widely, so plants should confirm against their own tariff.

Common questions

  • How do you calculate a sign's energy cost? Multiply connected load in kW by runtime in hours and the energy rate per kWh. A 12 kW load running 8 hr at $0.12/kWh costs $11.52 for that run.
  • How much energy does an illuminated sign use per day? Multiply load by runtime. The example draws 12 kW for 8 hr, using 96 kWh in a day before you apply the price.
  • What is the cost per unit to keep a sign lit? Divide the run's energy cost by the number of illuminated units. Here $11.52 across 1,000 units is about $0.0115 per piece per run.
  • Does this size the power supply's wattage? It sizes the operating cost from the connected load you enter; to spec the actual supply, add headroom (often 20%) above measured load so drivers are not run at full capacity continuously.
  • Why does per-unit cost matter for signage? It lets you compare designs and justify LED efficiency. A cost of $0.0115 per illuminated unit per run is easy to show a client when defending a retrofit's payback.

Last reviewed 2026-05-12.