IFTA Tax Calculator
Calculate your quarterly IFTA fuel tax obligation across all 48 continental states. Enter your miles and fuel purchases to see exactly what you owe — or what credits you're entitled to.
Understanding IFTA and Your Filing Obligations
The International Fuel Tax Agreement (IFTA) applies to any carrier operating a qualified motor vehicle — over 26,000 lbs or with 3+ axles — across state lines. If that describes your operation, you file quarterly returns reporting miles driven and fuel purchased in each jurisdiction. The math is straightforward but tedious: each state calculates taxable gallons based on your fleet MPG, then applies its own tax rate. States where you bought more fuel than you consumed give you a credit; states where you drove more than you fueled owe a balance. Getting it wrong means penalties and interest, and the filing deadlines (April 30, July 31, October 31, January 31) come up fast.
This calculator does the heavy lifting. Enter your miles driven and gallons purchased per state, and it computes your net tax or credit for each jurisdiction instantly. It accounts for current state tax rates and surcharges so you can estimate your quarterly liability before you sit down with your accountant. For a deeper walkthrough of the filing process, read our IFTA filing guide.
Keep in mind: this tool provides estimates for planning. Your official filing should use actual mileage records and fuel receipts through your base jurisdiction's IFTA portal. But having a reliable estimate before filing season means no surprises — and better cash flow planning all quarter long.
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Frequently Asked Questions
IFTA (International Fuel Tax Agreement) is a fuel tax collection agreement between 48 US states and 10 Canadian provinces. If you operate a qualified motor vehicle (over 26,000 lbs or 3+ axles) across state lines, you must file quarterly IFTA returns reporting miles driven and fuel purchased in each jurisdiction.
IFTA returns are filed quarterly. Q1 (Jan-Mar) is due April 30, Q2 (Apr-Jun) is due July 31, Q3 (Jul-Sep) is due October 31, and Q4 (Oct-Dec) is due January 31. Late filings incur penalties and interest.
IFTA calculates fuel tax owed per state based on miles driven in that state divided by your fleet MPG. This gives you 'taxable gallons' — the fuel you theoretically consumed in that state. If you purchased more fuel than you consumed in a state, you get a credit. If you consumed more than you purchased, you owe tax at that state's rate.
As of current rates, California, Pennsylvania, Indiana, and Washington have some of the highest diesel fuel tax rates, while Alaska, Oklahoma, and Mississippi have among the lowest. Tax rates change periodically, so always verify with your state's IFTA office before filing.
No. This calculator provides estimates for planning purposes. For your official quarterly filing, use your actual mileage records and fuel receipts, and file through your base jurisdiction's IFTA portal or through your accountant.
Let Us Handle the Paperwork
Our dispatchers track your miles and fuel purchases so you always have accurate data when IFTA filing time comes around.