IFTA Calculator

If you're running under your own authority and crossing state lines in a commercial vehicle, you almost certainly need an IFTA license. Missing this requirement doesn't just mean a penalty — it can mean a roadside citation, a fine of up to $500 per violation in some states, and a compliance flag that shows up on your safety score.

Which vehicles require IFTA registration

IFTA applies to qualified motor vehicles, defined as: - Any vehicle with two axles and a gross vehicle weight or registered gross vehicle weight exceeding 26,000 lbs - Any vehicle with three or more axles, regardless of weight - Any combination vehicle (truck + trailer) with a combined weight exceeding 26,000 lbs

This covers the vast majority of semi-trucks, most Class 7 and Class 8 trucks, and many Class 6 vehicles when pulling a loaded trailer. Box trucks under 26,000 lbs that stay intrastate are generally exempt. Recreational vehicles, government vehicles, and certain farm vehicles may also be exempt depending on the state.

IFTA covers 48 contiguous US states and 10 Canadian provinces. Alaska, Hawaii, and the District of Columbia are not members. If you only operate within one IFTA jurisdiction, you don't file IFTA — you just pay that jurisdiction's fuel taxes at the pump.

How to register for IFTA

You register through your base jurisdiction — the state where your truck is registered or where your business operates. Most states allow online registration through their department of transportation or motor carrier services. Once approved, you receive an IFTA license (keep it in the cab) and two decals per vehicle (one for each side of the truck cab).

IFTA licenses renew annually on January 1. Most states process renewals in October and November. There's typically a small fee — usually $10–$25 per vehicle per year — which is essentially the cost of the administrative system.

Quarterly filing deadlines

IFTA returns are due four times per year: - Q1 (January 1 – March 31): Due April 30 - Q2 (April 1 – June 30): Due July 31 - Q3 (July 1 – September 30): Due October 31 - Q4 (October 1 – December 31): Due January 31

Miss a deadline and you're looking at a penalty of $50 or 10% of the net tax due, whichever is greater. That's on top of interest charges on any unpaid balance. Most state portals allow online filing and electronic payment, and filing even a zero return on time avoids all penalties.

What you need to file

You'll need state-by-state mileage totals, state-by-state fuel purchase totals, and your fleet MPG for the quarter. That's it. The math is straightforward once you have the data — which is exactly what this calculator handles.

The IFTA record-keeping requirement is simple in concept: you need to know how many miles you drove in each state and how many gallons you purchased in each state, every quarter, for four years. In practice, making that data audit-ready is where most owner-operators fall short.

Mileage records: what counts

State-by-state mileage can come from several sources. Your ELD (electronic logging device) is the gold standard — most modern ELDs track GPS position and can generate state mileage summaries automatically. This data is timestamped, difficult to falsify, and exactly what an IFTA auditor wants to see.

Paper trip logs are still acceptable but require discipline. Every trip log should show the date, origin, destination, vehicle unit number, and odometer readings at each state line crossing. If you use paper logs, keep a consistent format and don't mix daily log pages with trip log pages.

GPS records, toll receipts, and load confirmation documents all serve as corroborating evidence, but they don't replace a mileage summary by jurisdiction. Some fleet management software — including popular ELD platforms like KeepTruckin (now Motive), Samsara, and Omnitracs — generates IFTA mileage reports directly, which can save hours per quarter.

Fuel purchase records

Every fuel purchase must be documented with a receipt showing: - Date of purchase - Seller name and address - Number of gallons purchased - Fuel type (diesel) - Vehicle unit number or plate number - Price per gallon (optional but useful)

Credit card statements alone are not sufficient. You need actual receipts. If you're paying cash for fuel, get a printed receipt every time — no exceptions. Bulk fuel purchased from your own tank at a yard requires a separate bulk fuel log showing date, quantity, and vehicle.

Reefer fuel and DEF do not count toward IFTA. Only diesel (or alternative fuels) used to power the vehicle's engine is reportable.

What triggers an IFTA audit

IFTA audits are conducted by your base jurisdiction and cover all jurisdictions simultaneously. Auditors look for:

• MPG anomalies: If your fleet MPG on the return is dramatically different from quarter to quarter (say, 6.8 MPG one quarter and 4.1 the next), that flags inconsistent record-keeping.
• Missing receipts: Fuel purchases without documentation get disallowed, which increases your net taxable gallons and your tax bill.
• Mileage inconsistencies: If your reported state miles don't add up to your total odometer difference, auditors notice.
• Large refund claims: Consistently claiming refunds — especially large ones — draws scrutiny.

The best audit defense is a consistent process: same method for tracking miles every quarter, receipts organized by quarter in a folder or digital storage, and MPG that makes sense for your equipment and operations. A good IFTA audit is boring — auditors verify your math, check a sample of receipts, and send you on your way.

Digital tools that make this easier

Modern ELD platforms like Motive, Samsara, and BigRoad generate IFTA mileage reports as a standard feature. Fuel card programs from companies like EFS (now WEX), Comdata, and Pilot Flying J provide detailed purchase reports that already include all required fields. If you're not using both, you're doing this the hard way.

One of the more counterintuitive aspects of IFTA is that filing it correctly can actually put money back in your pocket. Owner-operators who run heavy interstate miles often end up with a net IFTA refund because of how fuel purchasing patterns interact with state-by-state tax rates. Understanding the rate landscape helps you predict your quarterly position before you file.

How state IFTA rates are structured

Each IFTA member jurisdiction sets its own diesel fuel tax rate, expressed in cents per gallon. These rates change periodically — most states update annually, some adjust quarterly. The range is significant: as of 2026, state diesel tax rates span from around $0.12/gallon at the low end to over $0.60/gallon for certain states, with surcharges pushing California's effective rate higher still.

Some states also have additional surcharges layered on top of the base rate. Indiana, for example, adds a surcharge on top of its base rate. Kentucky and Virginia have rate structures that include both a fixed excise tax and a percentage-based component. When calculating IFTA, it's the total effective rate per gallon that matters — which is what this calculator uses.

States with notably high effective rates (2026)

California consistently tops the list with one of the highest effective diesel tax rates in the country. Pennsylvania, Indiana, and Washington also have high effective rates. If you run I-80 or I-90 through these states regularly, you're consuming significant fuel in high-tax jurisdictions.

States with lower effective rates

Mississippi, Louisiana, and several southeastern states have lower base rates, which is one reason southeastern lanes tend to have lower fuel costs relative to distance. Wyoming and New Mexico are also on the lower end. If you're purchasing fuel in these states and driving most of your miles in higher-tax states, you'll typically see a balance due on your IFTA return.

Reading the per-jurisdiction breakdown

When you calculate IFTA, each state line in the results shows the same structure: - Miles driven in that jurisdiction - Taxable gallons consumed (miles ÷ MPG) - Gallons purchased in that jurisdiction - Net taxable gallons (consumed minus purchased) - Tax rate for that state - Tax due or credit

A positive amount means you consumed more than you purchased there — you owe that state's tax authority for the difference. A negative amount means you purchased more than you consumed — you get credit. The net of all rows is your quarterly IFTA balance.

A practical example

Say you run from Atlanta to Chicago and back, weekly, for a full quarter. You do most of your fueling in Tennessee and Kentucky (lower rates), but you drive significant miles in Illinois and Indiana (higher rates). Your IFTA return will likely show balances due in Illinois and Indiana, offset by credits from Tennessee and Kentucky. The net might be $150–$400 due depending on total miles and your fleet MPG.

Flip the scenario: you run Southeast to California and you fuel up in California every time (high rate), but most of your deadhead miles are in Nevada and Arizona (lower rates). You'd likely see a credit from California offsetting smaller balances in the other states, potentially resulting in a net refund.

This is why operating patterns matter as much as fuel prices when thinking about your quarterly IFTA position — and why running this calculator before the deadline gives you time to budget for what's coming.