How much does it cost to charge a Hyundai Ioniq 9 at home in Idaho?
$17.61 for a full charge
- Per 100 miles
- $5.26
- A month at 1,000 miles
- $52.59
- Per mile
- 5.3¢
- Gas at 30 mpg, same miles
- $149.33
2026 Hyundai Ioniq 9 S RWD, EPA 36.6 kWh per 100 miles, at Idaho’s average rate of 14.4¢ per kWh (EIA, June 2026). Filling the 110.3 kWh battery from empty takes about 123 kWh from the wall at 90% charging efficiency. How we calculate this
Electricity versus gasoline
| Hyundai Ioniq 9 | Gas car | Difference | |
|---|---|---|---|
| Per 100 miles | $5.26 | $14.93 | $9.67 |
| A month (1,000 mi) | $52.59 | $149.33 | $96.74 |
| A year (12,000 mi) | $631.13 | $1,792.00 | $1,160.87 |
Home charging beats gas for this car as long as electricity costs less than 40.8¢ per kWh. Negative differences mean the gas car is cheaper. The 30 mpg comparison car is our assumption; see the methodology.
What it costs at other monthly mileages
| Miles a month | Energy | Electricity | Gas (30 mpg) |
|---|---|---|---|
| 500 | 183 kWh | $26.30 | $74.67 |
| 750 | 275 kWh | $39.45 | $112.00 |
| 1,000 | 366 kWh | $52.59 | $149.33 |
| 1,500 | 549 kWh | $78.89 | $224.00 |
| 2,000 | 732 kWh | $105.19 | $298.67 |
Charging in Idaho compared with other states
Idaho’s residential rate is the 10th cheapest of 51 states and DC, 4.0¢ below the US average of 18.3¢ (−22%). Idaho’s rate is up 2.3¢ from June 2025 (12.1¢, +19.1%).
Ways to spend less
- Ask your utility about a time-of-use or EV rate and schedule charging for off-peak hours; the car or charger can do it automatically.
- Precondition the cabin while the car is still plugged in, so heating or cooling comes from the grid instead of the battery.
- Keep tires at the pressure on the door-jamb sticker; underinflated tires raise consumption.
- Drive 100 fewer miles a month: saves $5.26 at 14.4¢ per kWh.
Questions
How much does it cost to fully charge a Hyundai Ioniq 9 in Idaho?
About $17.61. Filling the 110.3 kWh battery from empty takes about 123 kWh from the wall at 90% charging efficiency. at 14.4¢ per kWh.
How much does it cost to charge a Hyundai Ioniq 9 per month?
About $52.59 a month at 1,000 miles (14.4¢ per kWh), or $631.13 a year in Idaho. At the EPA rating of 36.6 kWh per 100 miles, 1,000 miles take 366 kWh from the wall.
How much does it cost to charge a Hyundai Ioniq 9 per mile?
5.3¢ a mile, or $5.26 per 100 miles in Idaho.
Is charging a Hyundai Ioniq 9 cheaper than gas?
Yes in Idaho: $5.26 per 100 miles against $14.93 for a 30 mpg car at $4.48 a gallon (AAA, September 24, 2026). It stays cheaper as long as electricity costs less than 40.8¢ per kWh.
How many kWh does it take to charge a Hyundai Ioniq 9?
Filling the 110.3 kWh battery from empty takes about 123 kWh from the wall at 90% charging efficiency. Most charging sessions top up part of the battery, so a typical night uses less.
How does charging in Idaho compare with other states?
Idaho’s residential rate is the 10th cheapest of 51 states and DC, 4.0¢ below the US average of 18.3¢ (−22%). Idaho’s rate is up 2.3¢ from June 2025 (12.1¢, +19.1%).
Sources
- EPA rating carrier: S RWD 92 MPGe, 335 mi; SE/SEL AWD 88 MPGe 320 mi; Performance 85 MPGe 311 mi
- EPA rating carrier: All 2026 Ioniq 9 use 110.3 kWh pack
- U.S. EPA and DOE, fueleconomy.gov (official ratings; verify here)
- AAA, national average price of regular gasoline, September 24, 2026
- U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A: average price of electricity to ultimate customers, residential, June 2026 Figures transcribed from republications of this table on September 26, 2026; pending direct verification from the EIA API.
- Carrier page: June 2026 residential average price, citing EIA Electric Power Monthly Table 5.6.A
Usage assumptions (hours a day, season) are ours and listed on the methodology page. Found an error? Tell us.