42 cents, in the United States, for a mainstream 100 W machine. That is 2.4 kWh at 17.5 cents.
A full day of printing is the case people worry about, and it is worth putting the figure next to something familiar: 2.4 kWh is roughly what an electric kettle uses in half an hour of boiling.
The same day, four ways
| Energy | Cost | |
|---|---|---|
| 60 W small machine, US rate | 1.44 kWh | $0.25 |
| 100 W mainstream machine, US rate | 2.4 kWh | $0.42 |
| 100 W mainstream machine, German rate | 2.4 kWh | €0.92 |
| 250 W large-format machine, US rate | 6 kWh | $1.05 |
The widest spread on that table is not the machines — it is the countries. The same printer doing the same day costs more than twice as much in Germany as in the United States, and close to five times as much in Germany as in India.
Wattage is not constant across the day
The figures above use a single steady-state number, which is the honest simplification. In reality a print draws hardest in the first few minutes while the bed comes up, then settles.
That heat-up peak looks alarming and contributes almost nothing. Even an 850 W enclosed machine pulling its peak for a full minute uses 0.014 kWh — a quarter of a cent at the US rate. It is the twenty-four hours after it that make the bill.
Where a long print does get expensive
Not in power. In the other three terms.
A 24-hour print is 24 hours of machine time, and at even a modest 30 cents an hour that is $7.20 of wear — seventeen times the electricity. It is also 24 hours of exposure to anything that can go wrong, which is why long prints justify a higher failure allowance than short ones rather than the same one.
If cost is the reason you are hesitating over an overnight job, the electricity is not the thing to think about.
Set your own wattage and rate in the print cost calculator, and check your region in the electricity rate table.