How Much Electricity Does An Electric Water Heater Use?
An electric water heater typically uses about 4,500 watts while running. At 3 hours a day that is 13.5 kWh per day, 405 kWh per month and 4,928 kWh per year.
Calculate your own cost
- Per hour
- $0.7884.5 kWh
- Per day
- $2.3613.5 kWh
- Per week
- $16.5494.5 kWh
- Per month (30 days)
- $70.88405 kWh
- Per year
- $862.314,928 kWh
Formula: watts ÷ 1,000 × hours × rate. Edit any box and every number updates instantly.
People also ask
How much does a 4,500-watt electric water heater cost per hour?
At $0.175/kWh, it costs $0.788 per hour. The maths: 4,500 W ÷ 1,000 = 4.5 kWh per hour, × $0.175 = $0.788.
How much does it cost per month?
Used 3 hours a day for 30 days, it costs about $70.88 per month and uses 405 kWh. Change the hours in the calculator above to match how you use it.
How many kWh does it use?
13.5 kWh per day, 405 kWh per month and 4,928 kWh per year at 3 hours a day. A kWh is one kilowatt (1,000 W) used for one hour. It is the unit on your electricity bill.
How can I lower the cost?
Set the tank to 120°F (49°C), insulate the pipes and fix dripping hot taps. Check your bill for the exact rate and enter it above.
Does my electricity rate change the answer?
Yes, a lot. At 10¢ per kWh the monthly cost is $40.50 and at 30¢ it is $121.50. Find your rate on your bill (total cost ÷ kWh used) and type it into the calculator.
Cost by hours of use
| Used per day | Energy per day | Cost per day | Cost per month | Cost per year |
|---|---|---|---|---|
| 1 hour | 4.5 kWh | $0.788 | $23.63 | $287.44 |
| 2 hours | 9 kWh | $1.58 | $47.25 | $574.88 |
| 3 hours | 13.5 kWh | $2.36 | $70.88 | $862.31 |
| 4 hours | 18 kWh | $3.15 | $94.50 | $1,149.75 |
| 5 hours | 22.5 kWh | $3.94 | $118.13 | $1,437.19 |
| 6 hours | 27 kWh | $4.73 | $141.75 | $1,724.63 |
| 7 hours | 31.5 kWh | $5.51 | $165.38 | $2,012.06 |
| 8 hours | 36 kWh | $6.30 | $189.00 | $2,299.50 |
| 9 hours | 40.5 kWh | $7.09 | $212.63 | $2,586.94 |
| 10 hours | 45 kWh | $7.88 | $236.25 | $2,874.38 |
| 11 hours | 49.5 kWh | $8.66 | $259.88 | $3,161.81 |
| 12 hours | 54 kWh | $9.45 | $283.50 | $3,449.25 |
| 13 hours | 58.5 kWh | $10.24 | $307.13 | $3,736.69 |
| 14 hours | 63 kWh | $11.03 | $330.75 | $4,024.13 |
| 15 hours | 67.5 kWh | $11.81 | $354.38 | $4,311.56 |
| 16 hours | 72 kWh | $12.60 | $378.00 | $4,599.00 |
| 17 hours | 76.5 kWh | $13.39 | $401.63 | $4,886.44 |
| 18 hours | 81 kWh | $14.18 | $425.25 | $5,173.88 |
| 19 hours | 85.5 kWh | $14.96 | $448.88 | $5,461.31 |
| 20 hours | 90 kWh | $15.75 | $472.50 | $5,748.75 |
| 21 hours | 94.5 kWh | $16.54 | $496.13 | $6,036.19 |
| 22 hours | 99 kWh | $17.33 | $519.75 | $6,323.63 |
| 23 hours | 104 kWh | $18.11 | $543.38 | $6,611.06 |
| 24 hours | 108 kWh | $18.90 | $567.00 | $6,898.50 |
How we worked it out
- Energy per hour: 4,500 W ÷ 1,000 = 4.5 kWh
- Cost per hour: 4.5 kWh × $0.175 = $0.788
- Cost per day: × 3 hours = $2.36
- Month and year: × 30 days = $70.88, × 365 days = $862.31
About electric water heater running costs
Tank water heaters use heavy elements (usually 4,500 W) but only run for a few hours a day to keep water hot. The hours here mean element-on time.
Typical sizes: 3,000 W, 4,500 W, 5,500 W.
How to spend less: Set the tank to 120°F (49°C), insulate the pipes and fix dripping hot taps.
What this estimate assumes
- The appliance draws its full stated wattage the whole time it is on. Real units with a thermostat cycle off and cost less.
- Wattage is the typical label value, not a measured value. Check the label on your own appliance.
- The rate is an approximate residential average. Your bill may include fixed fees, tiers or time-of-use pricing. Edit the rate above.
- A month is 30 days and a year is 365 days.