How it works
kWh per print = power (W) × time (h) ÷ 1000. cost per print = kWh × rate ($/kWh). per month = cost per print × prints per month.
Electricity is billed by the kilowatt-hour — the energy of 1,000 watts running for one hour. So the whole calculation is just power times time, converted to kilowatt-hours, times your price per kWh. A printer that averages 120 watts over a 6-hour print uses 120 × 6 ÷ 1,000 = 0.72 kWh; at the 2025 US average of about 17.3 cents per kWh that is roughly 12 cents for the print. Run twenty such prints a month and you are at about 14.4 kWh and $2.45 — small for a hobbyist, but it scales linearly, so a farm of machines running around the clock adds up to a real line item. The number that matters most is the average power draw, not the power supply’s rating: a 350-watt supply might only pull 100–120 watts on average once the bed is up to temperature, because the heaters cycle on and off. If you can, measure it with a plug-in energy meter during a real print; otherwise use the guide values in the field hint. Your electricity rate also varies a lot by state, so enter the figure from your own bill for the most accurate result.
Sources
- Energy = power × time (kilowatt-hour definition) U.S. Energy Information Administration, "Electricity explained: Measuring electricity." One watt-hour is the energy of one watt used for one hour; a kilowatt-hour is 1,000 watt-hours.
- US average electricity price (default rate) U.S. Energy Information Administration, "Electricity explained: Factors affecting electricity prices." 2025 US average residential price ≈ 17.30¢ per kWh, with wide variation by state.
FAQ
How much electricity does a 3D printer use?
Take the printer’s average power draw in watts, multiply by the print time in hours, and divide by 1,000 to get kilowatt-hours. A typical bed-heated FDM printer averaging 120 watts uses about 0.72 kWh for a 6-hour print. At the US average rate of roughly 17.3 cents per kWh, that print costs about 12 cents of electricity. Resin printers usually draw less, often 30–70 watts, so they cost even less per hour to run.
Is it expensive to run a 3D printer?
For a hobbyist, no. Even printing daily, a single desktop machine usually adds only a few dollars a month to your electricity bill — far less than the filament it consumes. It becomes a real cost at scale: a print farm with many machines running continuously can use hundreds of kilowatt-hours a month. Enter your prints-per-month and rate to see your own monthly figure rather than relying on a rule of thumb.
What power draw should I use for my printer?
Use the average watts drawn during a print, not the power supply’s maximum rating. The heated bed is the biggest draw and it cycles on and off, so a printer with a 350-watt supply might average only 100–120 watts once it is up to temperature. A plug-in energy meter gives the most accurate figure; without one, use roughly 30–70 watts for resin or small FDM printers, 80–150 watts for a bed-heated FDM printer, and 200 watts or more for large or high-temperature machines.
Does the heated bed use most of the power?
On an FDM printer, yes. The heated bed is usually the single largest electrical load, followed by the hotend and then the motors, fans and electronics. That is why average draw is much lower than the peak: the bed pulls hard while heating up, then settles into cycling on and off to hold temperature. Printing without a heated bed, or at a lower bed temperature, noticeably reduces energy use — which is one reason resin and non-heated setups cost less to run.
How do I lower my 3D printing electricity cost?
The rate you pay matters most, so if you can, run long prints during off-peak hours if your utility has time-of-use pricing. Beyond that, an enclosure holds heat so the bed cycles less, a lower bed temperature (where the material allows) cuts the biggest load, and batching prints avoids repeated heat-up cycles. Because electricity is usually a small share of a print’s total cost, though, filament, failures and labor are where the bigger savings are — see the full cost calculator.
Estimates only. Actual energy use depends on your printer’s real average power draw, bed and chamber temperatures, ambient conditions and print settings; electricity rates vary by region and time of day. Measure with an energy meter and use your own tariff for the most accurate figure.