How much is the gas tax in Hawaii?

Hawaii charges a state gasoline excise of $0.16 per gallon, plus a county fuel tax that varies by island — roughly $0.165 on Oahu and as much as $0.23 on Maui and Hawaii County. Add the $0.184 federal excise and the combined per-gallon tax usually lands between $0.49 and $0.57.

Does Hawaii's county fuel tax really differ by island?

Yes. Each county sets its own fuel tax on top of the state rate. Honolulu, Maui, Hawaii County, and Kauai all charge different amounts, so the same gallon of gas carries a different total tax depending on which island you fill up on. Adjust the county field to match your island.

Does this include Hawaii's General Excise Tax?

No. This tool shows the per-gallon excise taxes only. Hawaii also applies its General Excise Tax of about 4.5% to the retail fuel price, which adds several more cents per gallon and is not counted in the excise figures here.

How is the per-mile gas tax figured?

Tax per mile equals the combined per-gallon tax divided by your vehicle's miles per gallon. A car getting 26 mpg paying about $0.51 per gallon in tax owes roughly $0.02 of fuel tax for every mile driven.

Will this match my exact receipt?

It estimates the excise portion of what you pay. Your pump price also bundles the General Excise Tax and shipping costs that make Hawaii fuel pricey. Update the rate fields for your island and the current year for the best accuracy.

Hawaii Gas Tax Calculator

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Hawaii drivers pay a layered fuel tax: a flat state excise, a county fuel tax that changes from island to island, and the federal excise that applies everywhere. This calculator turns those per-gallon rates into the numbers that actually matter to you — tax per fill-up, tax per mile, and the total fuel tax you pay over a year.

How it works

The taxes are simple per-gallon excises that add together and then scale with how much fuel you burn. The combined rate is the sum of the state excise ($0.16), your island’s county fuel tax, and the federal excise ($0.184). From there:

Tax per fill-up = combined rate × tank size
Gallons per year = annual miles ÷ miles per gallon
Annual fuel tax = gallons per year × combined rate
Tax per mile = combined rate ÷ miles per gallon

Combined per-gallon tax = state excise + county fuel tax + federal excise.

Because the county portion is set independently by Honolulu, Maui, Hawaii County, and Kauai, the same gallon of gas carries a different total tax depending on where you fill up.

Example and notes

Suppose you drive 12,000 miles a year at 26 mpg on Oahu, where the county fuel tax is about $0.165. The combined per-gallon excise is roughly $0.16 + $0.165 + $0.184 = $0.509. You burn about 462 gallons a year, so your annual fuel excise is around $235, or about $0.02 per mile.

That figure is the excise portion only. Hawaii layers its General Excise Tax (about 4.5%) on the retail price at the pump, and shipping costs make Hawaii fuel among the most expensive in the country — so your actual out-of-pocket cost runs higher than the excise alone. Everything is computed in your browser; nothing about your vehicle or mileage is uploaded.