Free tool
IFTA Quarterly Tax Calculator
Enter miles and gallons per jurisdiction, get fleet MPG, per-jurisdiction tax breakdown, and the net balance owed (or refund expected) at your IFTA base jurisdiction.
Computed client-side. Your trip records never leave your browser.
Calculator
How IFTA tax math actually works
Before IFTA, an interstate trucking company had to file a separate fuel-tax return in every state it operated in. A carrier that ran loads from Texas to New Jersey might file in 10+ states every quarter, each on its own form, each with its own deadline, each demanding the same trip data formatted differently. IFTA replaced all of that with one quarterly filing to your base jurisdiction.
Your base jurisdiction is the IFTA-member state or province where you have an established business address, where your operational records are kept, and where some of your fleet is registered. You can have exactly one base jurisdiction at a time. The base jurisdiction issues your IFTA license and decals, collects your quarterly net tax, and apportions revenue to every other jurisdiction you reported miles in.
The fleet-MPG step is the heart of IFTA. You compute your fleet’s actual miles-per-gallon for the quarter:
fleet MPG = total taxable miles ÷ total gallons purchased
Then for each jurisdiction, gallons consumed in that jurisdiction = miles driven there ÷ fleet MPG. That consumption number, multiplied by the jurisdiction’s current tax rate, is the tax you owe. The tax you paid in that jurisdiction is gallons purchased there × that same rate (you already paid that tax at the pump). The difference is your net for that jurisdiction.
Sum every jurisdiction’s net to get your quarterly balance. A positive number is what you remit; a negative number is a refund your base jurisdiction will issue after processing.
The math is deliberately neutral on where you bought fuel. A carrier who buys all its fuel in low-tax Oklahoma but drives most of its miles in high-tax California ends up owing California the difference, because tax follows miles, not pumps. The opposite is also true — buy a tank in California, drive most miles in Oklahoma, and you’ll get a refund credit on the California over-purchase.
The three surcharge states
Indiana, Kentucky, and Virginia publish a per-gallon surcharge on top of the base diesel rate. The surcharge is collected directly from the carrier, not at the pump, so it doesn’t net out against fuel purchases — it’s pure per-mile additional tax. On the IFTA return, the surcharge appears as a separate row for that jurisdiction (per IFTA Inc. Procedures Manual P530 §IV.B).
A typical IN trip: 1,000 miles driven in Indiana at 6 MPG = 167 gallons consumed × $0.57 base rate = $94.95 tax owed (offset by your fuel purchases at the pump), plus 167 gallons × $0.55 surcharge = $91.85 surcharge owed (no offset). Total IN row on the return: ~$94.95 base + ~$91.85 surcharge.
The calculator sums the surcharge into your net balance automatically but breaks it out in the per-jurisdiction table so you can match the layout of the IFTA return when you transcribe.
Oregon is the odd one
Oregon is the only US state that taxes commercial vehicles on a weight-mile basis instead of a per-gallon fuel basis. Oregon IS an IFTA member, but the fuel tax line on the IFTA return reads $0 for OR miles. The weight-mile tax is filed separately through the Oregon Department of Transportation, with its own quarterly reporting cadence (Oregon Form 9410).
If you drive in Oregon, the IFTA calculator above shows OR with a $0 fuel-tax line — that part of your IFTA obligation is genuinely $0. Plan separately for the Oregon weight-mile filing.
Common IFTA mistakes
Treating “non-taxable” miles as taxable.
Off-highway miles (yard moves, private property) are not IFTA-taxable. So are some toll-road miles in jurisdictions that exempt toll mileage. Many ELD reports include all miles indiscriminately — you need to separate taxable miles before feeding numbers into IFTA.
Missing the bulk-fuel detail.
Fuel pulled from your own bulk tank is taxable differently than retail pump purchases. If you paid state fuel tax when filling the bulk tank, the gallons pulled count as tax-paid; if you bought the bulk fuel tax-exempt, they don’t. The IFTA return has separate sections for these.
Filing a $0 return late.
Even when your net balance is $0 or a small refund, the return is still required by the quarterly deadline. Late-filed returns trigger penalties and can suspend your IFTA license, which suspends your operating authority.
Mixing fuel types in fleet MPG.
IFTA fleet MPG is computed per fuel type. If you run both diesel tractors and gasoline service trucks under one IFTA license, you compute two fleet MPGs — one for diesel miles+gallons, one for gasoline. Don’t commingle.
Frequently asked questions
- What is IFTA?
- IFTA is the International Fuel Tax Agreement — a single quarterly fuel-tax reporting agreement among the 48 contiguous US states (no Hawaii), the District of Columbia, Alaska, and 10 Canadian provinces plus the Yukon Territory. Instead of filing a separate fuel-tax return in every state you operate in, you register in your BASE jurisdiction, run one set of decals, and file one quarterly return. The base jurisdiction collects net tax and distributes the right share to every other jurisdiction you reported miles in.
- Who has to file IFTA?
- A commercial motor vehicle is an IFTA-qualified vehicle if it (a) has a taxable gross vehicle weight over 26,000 lbs, OR (b) has three or more axles regardless of weight, AND (c) is used in two or more IFTA jurisdictions. Owner-operators with a single qualifying tractor file IFTA. Buses over the 26,000-lb threshold operating across state lines also file. Vehicles operated within a single jurisdiction do not need IFTA, but state-only fuel-tax filings still apply.
- How is IFTA tax calculated?
- The formula is: fleet MPG = total taxable miles ÷ total gallons purchased. For each jurisdiction: gallons consumed = miles driven there ÷ fleet MPG; tax owed = gallons consumed × that jurisdiction's tax rate; tax paid = gallons purchased there × the same rate. Net = tax owed minus tax paid. Sum every jurisdiction's net to get your quarterly balance. If positive, you remit; if negative, your base jurisdiction issues a refund.
- What if I drove through a jurisdiction but bought no fuel there?
- You still owe tax on the miles you drove there — tax follows MILES driven, not fuel purchased. Your fleet MPG converts the miles into taxable gallons; the jurisdiction's rate converts taxable gallons into tax owed; tax paid in that jurisdiction is $0 because you bought no fuel. So you owe the full per-mile amount to that jurisdiction. The other side: if you bought a lot of fuel in a jurisdiction but drove very few miles there, you'll get a refund credit for the over-purchase.
- Why does Oregon show a $0 tax rate?
- Oregon is an IFTA jurisdiction but uses a weight-mile tax instead of a fuel tax. So on the IFTA return, Oregon miles report $0 fuel tax owed. You still file a separate Oregon weight-mile report through the Oregon Department of Transportation — that filing is independent of IFTA.
- What are surcharge rates? (Indiana, Kentucky, Virginia)
- Indiana, Kentucky, and Virginia publish a per-gallon surcharge on top of the base diesel rate. The surcharge applies to MILES driven in that jurisdiction (same per-gallon math as the base rate) and is reported on a separate per-jurisdiction line on the IFTA return per IFTA Inc. Procedures Manual P530 §IV.B. The calculator sums the surcharge into the net balance but flags it separately so you can match the IFTA return layout.
- When are IFTA returns due?
- Quarterly: Q1 (Jan-Mar) is due April 30; Q2 (Apr-Jun) is due July 31; Q3 (Jul-Sep) is due October 31; Q4 (Oct-Dec) is due January 31 of the following year. File on time even if your net balance is $0 — late filings trigger penalties and put your IFTA license at risk.
- How current are these rates?
- The calculator uses the IFTA Inc. Q1 2025 rate matrix (published 2025-01-01). Quarterly rates revise on Jan 1 / Apr 1 / Jul 1 / Oct 1 — verify the current quarter against iftach.org/tax-matrix4.php before filing. The fleet-MPG and per-jurisdiction allocation math is timeless and matches IFTA Inc. Procedures Manual P530; only the rate numbers age.
- Does this calculator replace my filing software?
- No. This is a planning tool. The actual IFTA return goes to your base jurisdiction through that jurisdiction's revenue department portal (e.g. California CDTFA, Texas Comptroller, Ontario Ministry of Finance). Most carriers use a commercial IFTA filing service that imports ELD/GPS mileage and fuel-card receipts directly. Bindly Compliance does not file IFTA returns on your behalf.
Tracking IFTA across multiple tractors?
Bindly Compliance keeps your fleet’s mileage, fuel receipts, and every federal mandate on one calendar — MCS-150, HVUT, UCR, IFTA, IRP, all of them, with 90 / 60 / 30 day reminders. Pair with ELD imports and fuel-card APIs so the quarterly IFTA return drafts itself.