IFTA calculator: fuel tax and MPG by state
Enter the miles you drove and the gallons you bought in each state. You get your fleet MPG and the fuel tax you owe or get back in every state, at the rates for the quarter you are filing.
The arithmetic
How to calculate IFTA fuel tax
The return asks for the same four steps in every base state. The calculator above does them as you type.
1. Fleet MPG
All miles driven in the quarter, divided by all gallons bought. Round to two decimal places.
2. Taxable gallons
For each state: the miles driven there, divided by your MPG. Round to a whole gallon.
3. Net gallons
Taxable gallons, minus the gallons you bought in that state with tax paid at the pump.
4. Tax or credit
Net gallons times the state's rate. Above zero you owe that state. Below zero it owes you.
A worked example, Q3 2026 diesel
A truck drives 8,450 miles and buys 1,300 gallons in the quarter, so its MPG is 6.50.
| State | Miles | Taxable gallons | Gallons bought | Net gallons | Rate | Tax or credit |
|---|---|---|---|---|---|---|
| Texas | 5,150 | 792 | 800 | -8 | $0.2000 | $1.60 credit |
| Oklahoma | 1,900 | 292 | 500 | -208 | $0.1900 | $39.52 credit |
| Kentucky | 1,400 | 215 | 0 | 215 | $0.2200 | $47.30 due |
| Kentucky surcharge | 215 | $0.1050 | $22.58 due | |||
| Net for the quarter | 8,450 | 1,300 | $28.76 due |
Kentucky has no fuel bought in it, so every taxable gallon there is owed, and its surcharge is added on the same 215 gallons. Oklahoma shows a credit because more fuel was bought there than the miles used.
3rd quarter 2026
IFTA fuel tax rates by state
Final rates for July 1 to September 30, 2026, in U.S. dollars per gallon, as published by IFTA, Inc. Rates marked "changed" moved this quarter.
| State | Diesel | Gasoline |
|---|---|---|
| Alabama | $0.3100 | $0.3000 |
| Arizona | $0.2600 | $0.1800 |
| Arkansas | $0.2850 | $0.2470 |
| California | changed $0.9790 | None |
| Colorado | changed $0.3350 | changed $0.2800 |
| Connecticut | changed $0.4990 | $0.2500 |
| Delaware | $0.2200 | $0.2300 |
| Florida | $0.4097 | $0.4110 |
| Georgia | $0.3730 | $0.3330 |
| Idaho | $0.3200 | None |
| Illinois | $0.7380 | $0.6530 |
| Indiana | $0.6300 | changed None |
| Iowa | $0.3250 | $0.3000 |
| Kansas | $0.2600 | $0.2400 |
| Kentucky | $0.2200plus $0.1050 surcharge | $0.2500plus $0.0450 surcharge |
| Louisiana | $0.2000 | $0.2000 |
| Maine | $0.3120 | None |
| Maryland | changed $0.4745 | changed $0.4660 |
| Massachusetts | $0.2400 | $0.2400 |
| Michigan | $0.5240 | $0.5240 |
| Minnesota | $0.3260 | $0.3260 |
| Mississippi | changed $0.2400 | changed $0.2400 |
| Missouri | $0.2950 | $0.2950 |
| Montana | $0.2975 | None |
| State | Diesel | Gasoline |
|---|---|---|
| Nebraska | $0.3180 | $0.3180 |
| Nevada | $0.2700 | $0.2300 |
| New Hampshire | $0.2220 | None |
| New Jersey | $0.5610 | $0.4910 |
| New Mexico | $0.2100 | $0.1200 |
| New York | $0.3805 | changed $0.3980 |
| North Carolina | $0.4100 | $0.4100 |
| North Dakota | $0.2300 | $0.2300 |
| Ohio | $0.4700 | $0.3850 |
| Oklahoma | $0.1900 | $0.1900 |
| Oregon | None | None |
| Pennsylvania | $0.7410 | $0.5760 |
| Rhode Island | $0.4000 | $0.4000 |
| South Carolina | $0.2800 | $0.2800 |
| South Dakota | $0.2800 | $0.2800 |
| Tennessee | $0.2700 | $0.2600 |
| Texas | $0.2000 | $0.2000 |
| Utah | $0.3790 | changed $0.3190 |
| Vermont | $0.3100 | None |
| Virginia | changed $0.3360plus $0.1430 surcharge | changed $0.3260plus $0.1530 surcharge |
| Washington | changed $0.5950 | changed $0.5650 |
| West Virginia | $0.3570 | $0.3570 |
| Wisconsin | $0.3290 | $0.3290 |
| Wyoming | $0.2400 | $0.2400 |
| Province | Diesel | Gasoline |
|---|---|---|
| Alberta | $0.3519 | $0.3519 |
| British Columbia | $0.4060 | $0.3924 |
| Manitoba | $0.3383 | $0.3383 |
| New Brunswick | $0.4182 | $0.2942 |
| Newfoundland and Labrador | $0.2572 | $0.2030 |
| Nova Scotia | $0.4168 | $0.4196 |
| Ontario | $0.2436 | $0.2436 |
| Prince Edward Island | $0.3830 | $0.2293 |
| Quebec | $0.5468 | $0.5197 |
| Saskatchewan | $0.4060 | $0.4060 |
Reading the table
- None means IFTA, Inc. lists no rate for that fuel there. You still report the miles.
- A surcharge is a second line on the return for the same state, charged on taxable gallons.
- Provinces are shown in U.S. dollars per U.S. gallon, converted by IFTA, Inc. for the quarter.
- Footnotes in IFTA, Inc.'s matrix carry the exceptions, such as a rate that applies for only part of a quarter. Check them for any state marked "changed".
The calendar
IFTA quarters and due dates
A return is due by the last day of the month after each quarter. When that day falls on a weekend or legal holiday, it moves to the next business day.
| Quarter | Miles and fuel from | Return due |
|---|---|---|
| Q3 2026 | July 1 to September 30, 2026 | November 2, 2026October 31 is a Saturday |
| Q4 2026 | October 1 to December 31, 2026 | February 1, 2027January 31 is a Sunday |
| Q1 2027 | January 1 to March 31, 2027 | April 30, 2027 |
| Q2 2027 | April 1 to June 30, 2027 | August 2, 2027July 31 is a Saturday |
| Q3 2027 | July 1 to September 30, 2027 | November 1, 2027October 31 is a Sunday |
FAQ
IFTA calculator questions
How do you calculate IFTA tax?
Divide the total miles you drove in the quarter by the total gallons you bought. That is your fleet MPG, to two decimal places. For each state, divide the miles you drove there by the MPG to get taxable gallons, subtract the gallons you bought there with tax paid, and multiply what is left by that state's rate. A positive number is tax you owe that state. A negative number is a credit.
What MPG does the IFTA return use?
One average for the whole fleet and the whole quarter: every mile driven divided by every gallon put in the tanks, rounded to two decimal places. Miles and fuel outside IFTA, such as Alaska or Mexico, count in that average.
Do I report a state where I bought no fuel?
Yes. Every member state or province you drove in goes on the return. With no fuel bought there, all the taxable gallons for those miles are tax owed to that state.
What are the Kentucky and Virginia surcharges?
An extra per-gallon charge on top of the fuel tax, listed as its own line on the return. It is charged on taxable gallons, so fuel bought in the state does not reduce it and it is never a credit. For Q3 2026 the diesel surcharge is $0.1050 a gallon in Kentucky and $0.1430 in Virginia.
Why is the rate for Oregon zero?
IFTA, Inc. lists no fuel tax rate for Oregon. Oregon charges heavy trucks a weight-mile tax, filed with Oregon separately. Your Oregon miles still go on the IFTA return and count toward your MPG.
When is the IFTA return due?
By the last day of the month after the quarter ends: April 30, July 31, October 31 and January 31. When that day is a Saturday, Sunday or legal holiday, the return is due the next business day. The Q3 2026 return is due November 2, 2026.
Does this file my IFTA return?
No. You file the return with your base state, usually on its website. The calculator gives you the figures to file or to check a return against.
Is the calculator free?
Yes. There is no account and nothing to install, and the numbers you type stay in your browser.
Sources: IFTA, Inc. tax rate matrix, final rates for Q4 2025, Q1 2026, Q2 2026, Q3 2026, read October 7, 2026. IFTA Articles of Agreement R960 for due dates and the IFTA Procedures Manual P720 for the return's arithmetic.
The return is due four times a year. We email you before each one.
The tracker reminds you 30 and 7 days ahead of every IFTA return, and of your MCS-150, UCR, Form 2290 and IRP deadlines.