How Much Will A Dual Monitor Setup Increase Your Power Consumption?

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The amount of power consumed by a dual monitor set-up will obviously depend on the size and energy efficiency of the monitors you choose to hook up.

However, to provide an example a single 27” Dell S2715H monitor draws 24.5W of power, which will lead to a total  power consumption of 0.588kWh per week if used for 8 hours per day 

Using two of these monitors to create a dual monitor setup and operating them around the clock will account for an additional cost of 15.628 cents per day to your power bill (when using the average electricity rate across the US). 

With this baseline measurement established we were curious to know more.

So we bought a power meter, hooked up multiple monitors and truth tested a few assumptions.

We wanted to know…

  • How much does a dual monitor setup cost to power?
  • What impact does the brightness settings have upon the power consumption of a dual monitor setup?
  • How much power does a dual monitor set-up draw when left on standby?

How were these tests conducted?

To keep things simple, power ratings were recorded using a low cost power meter like this one on Amazon, which works by slotting into place between the appliance plug and the mains supply. 

They’re low cost and are nothing fancy and certainly not the most accurate piece of measuring equipment out there, but it does allow us a general idea of the peak/low and running wattage values, along with amperage and voltage. 

A digital power meter for computer monitors

How much does a dual monitor set-up cost to power?

After measuring the typical power consumption of as many different monitors we could find it made sense to collate them into a table. 

The cost of powering one and two of each of the monitors over a 40hr work week was calculated using the average electricity rate across all 50 states (as of 7 June 2021).

The most expensive dual setup in terms of power usage was 2 x Apple Thunderbolt displays, which added $1.06 of additional charges to our electricity bill each  week. 

Keep in mind that electricity rates can vary drastically from State to State.

By far and away the most expensive state for electricity is Hawaii, with consumers shelling out on average 32.97 cents for every kWh, whilst Oklahoma residents have  access to the cheapest rates at an average of 8.88 cents per kWh. 

Brand Model Monitor Size Avg. Power Consumption Power Cost Per 40hr Work Week (1 Monitor) Power Cost Per 40hr Work Week (2 Monitors)
Thunderbolt Display
Nitro EI Curved Gaming Monitor

What impact does brightness settings have upon the power consumption of a dual monitor setup?

A lot!

Our main test unit (Dell S2715H) recorded a 44.4% reduction in power usage simply by dimming the display  from full brightness down to half brightness.

Power drawn by a computer monitor on full brightness
Monitor brightness setting at 100%
Dell S2715H Power Rating @ 100% Brightness
Power drawn by a computer monitor on half brightness
Dell S2715H Power Rating @ 50% Brightness

How much power does a dual monitor setup draw whilst on standby?

The majority of power consumed by a monitor goes towards the light it produces, but when the screen is blank and the unit left on standby it will continue to draw power. 

Most modern monitors are designed to draw far less power when they enter “sleep” and “off” modes, so its not uncommon to record power consumption automatically dropping to less than 2W.

The ASUS – MB16AH goes as low as drawing an impressively low 0.05W after a period of inactivity.

The Dell Ultrasharp U2719DX is also a good example of energy efficiency, drawing only 0.5W when in sleep mode compared to a typical operating power of 26W.

0.5W this was the same result our test monitor obtained, which equalled a 98% reduction in power consumed. 

To save money, and be more environmentally sustainable seek out a monitor that is energy efficient. ‘Energy Star‘ certified products helps identify appliances that are energy efficient from those that are wasteful. 


How is monitor power consumption calculated?

Monitors have a power consumption rating that is measured in wattage (W), which is an expression of how much electricity is used at any one time.

All product specifications should include a value against operating power, standby power and off power.

To convert this power usage into a financial value we much change it into kWh.

A kilowatt hour (kWh) is a unit of energy that helps us describe how long it takes for 1,000 Watts to be used. 

As an example calculation a 1,000W appliance would take 1hr to use 1kWh, whereas a 100W appliance would take 10hrs to use 1 kWh. 

A 25W monitor would take 40hrs to use 1kWh, and so use 0.025kWh per hour (1 / 40 = 0.025).

How much does a kWh cost?

The average electricity rate across all 50 states (as of 7 June 2021) was 13.29 cents per kWh. 

Elsewhere in the world the average electricity rates vary from being far more expensive (Germany at 36 cents per kWh) right down to dirt cheap rates from nation states that are rich in oil supplies (Iran at 1 cent per kWh).

Statistic: Household electricity prices worldwide in September 2020, by select country (in U.S. dollars per kilowatt hour) | Statista
Find more statistics at Statista
Chris Dosser

Chris Dosser

Co-Founder of Eden Indoors

Enjoys sharing solutions to problems encountered whilst building and improving his own home office over the past 8 years. Environmental graduate with a love for biophilic design at home and houseplants. Obsessive about making information easier to understand and simpler to digest.

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