Hawaii Gas Tax Calculator
2026Calculate total gas tax per gallon in Hawaii, including the federal excise tax of $0.184/gal and HI state fuel taxes. Compare Hawaii gas and diesel tax rates for 2026.
Written and reviewed by Konstantin Iakovlev · Methodology · Updated
Fuel Needed
1.0 gal
Trip Cost
$4.10
Annual Cost
$1,066.00
Fuel Cost Breakdown
| Total Distance | 30.0 miles |
| Fuel Needed | 1.00 gallons |
| One-Way Cost | $4.10 |
| Trip Cost | $4.10 |
| Weekly Cost | $20.50 |
| Monthly Cost | $88.77 |
| Annual Cost | $1,066.00 |
Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.
How much is gas tax in Hawaii?
Every gallon of gasoline pumped in Hawaii carries two layers of tax: a federal excise tax of 18.4¢ per gallon (24.4¢ for diesel) collected by the IRS, and a state-level fuel tax of approximately 16¢ per gallon that funds Hawaii highway, bridge, and transit projects. Combined, that's roughly 34.4¢ per gallon in 2026.
Hawaii county fuel taxes: the 16¢ state rate is supplemented by county-level fuel taxes that vary significantly: Honolulu (Oahu) +18.5¢ (≈34.5¢ state+county), Maui +23¢ (≈39¢), Hawaii County (Big Island) +13¢ (≈29¢), and Kauai +13¢ (≈29¢). Adding the 18.4¢ federal excise on top, total all-in gasoline tax in Hawaii ranges roughly 47.4¢ to 57.4¢ per gallon depending on island. The Hawaii Department of Taxation publishes the current schedule.
State gas tax rates vary widely — from under 10¢/gal in Alaska to nearly 60¢/gal in California and Pennsylvania. Some states, including Hawaii, periodically adjust the rate via fuel-index formulas tied to wholesale prices or inflation, so the figure can drift mid-year. Many states also stack on smaller environmental, underground-storage-tank, or pre-paid sales-tax fees that aren't always shown at the pump but are baked into the posted price.
For a typical 12-gallon fillup in Hawaii, you contribute about $4.13 to combined road and federal infrastructure funds before any sales tax. Use the calculator above with your local pump price and tank capacity for an exact breakdown of pre-tax fuel cost vs. tax burden.
Hawaii fuel-tax history, indexing, and where the money goes
- Diesel state tax (2026)
- 16¢ per gallon
- Last increase
- 2007 (current 16¢ state rate set)
- Indexed?
- No — fixed until legislative action
- Where revenue goes
- State Highway Fund + County Highway Funds
Hawaii's 16¢ state gas tax has been unchanged since 2007. However, each of the four counties imposes its own substantial per-gallon county fuel tax: Honolulu (Oahu) +18.5¢, Maui +23¢, Hawaii County (Big Island) +13¢, Kauai +13¢. Combined with the 18.4¢ federal excise, total all-in fuel tax in Hawaii ranges 47.4¢ (federal+state-only) to 57.4¢ (Maui all-in) per gallon. The state revenue flows to highway maintenance; county portions fund local roads. Hawaii also imposes a 4% general excise tax that applies to the pre-tax fuel price.
Hawaii Tax Rates (2026)
| Federal Gas Tax | $0.184/gal |
| State Sales Tax | 4% |
| State Income Tax | progressive (up to 11.0%) |
| Avg. Property Tax Rate | 0.32% |
Gas tax — frequently asked questions
What is the federal gas tax in 2026?
The federal motor fuel excise tax is 18.4¢ per gallon on gasoline and 24.4¢ per gallon on diesel. The federal rate has been unchanged since 1993; only state and local taxes have moved. Federal revenue funds the Highway Trust Fund, which finances most interstate and bridge maintenance.
How much is gas tax by state?
State gas tax rates range from about 9¢/gal in Alaska to roughly 58¢/gal in California and Pennsylvania (the two highest). Washington (~49¢), New Jersey (~42¢), and Illinois (~47¢) round out the higher tier. Most states layer 20–40¢/gal of state tax on top of the 18.4¢ federal rate. Some states index gas tax to inflation; others raise it via legislation as needed.
Why does gas cost more at the pump than the rate suggests?
The pump price reflects crude oil cost, refining margin, distribution and retail markup, plus combined federal + state + local taxes. In high-tax states like California, taxes alone account for ~70¢/gallon. EV-charging stations are taxed differently (often by kWh, sometimes via a separate registration surcharge).
Are gas taxes deductible?
Gas taxes are not deductible on personal federal returns. Self-employed drivers using actual vehicle expenses can include fuel costs in business deductions, but the cleaner method is the IRS standard mileage rate ($0.70/mile in 2026), which already bundles fuel, depreciation, and maintenance.
Has gas tax changed in 2026?
Several states adjusted gas taxes in 2026 (most are inflation-indexed and reset at the start of the calendar year or fiscal year). Federal rates remain at 18.4¢/24.4¢ — unchanged since 1993. Many states are also adding EV registration fees ($100–$200/year) to recoup lost gas-tax revenue as electric vehicles displace combustion engines.