3,000 watts to kWh per day and month

72.00 kWh/day

for 3,000 W running 24/7 · 2,160 kWh/month · $356.40/month at 16.5¢

3,000 W by hours of use

Use	Per day	Per month	Cost/month
1 h/day	3.00 kWh	90.0 kWh	$14.85
2 h/day	6.00 kWh	180.0 kWh	$29.70
4 h/day	12.00 kWh	360.0 kWh	$59.40
8 h/day	24.00 kWh	720.0 kWh	$118.80
12 h/day	36.00 kWh	1,080.0 kWh	$178.20
24 h/day	72.00 kWh	2,160.0 kWh	$356.40

kWh = W × hours ÷ 1000. Devices with thermostats or compressors cycle, so actual use is often lower than the rated wattage × hours.

72.00 kWh running 24 hours, 24.00 kWh at 8 hours.