IFTA Fuel Tax Estimator
Estimate your quarterly IFTA tax position using total miles, total gallons, and a single average tax rate. Use this for budgeting and planning — file your official IFTA return with your base jurisdiction.
Simplified estimate — not for official IFTA filing.
Your Estimate
- Average MPG
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- Taxable Gallons
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- Net Tax Position
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How IFTA works
The International Fuel Tax Agreement (IFTA) simplifies fuel tax reporting for carriers operating in multiple U.S. states and Canadian provinces. Instead of filing separately with each state, you file one quarterly return with your base jurisdiction. IFTA then distributes tax revenue to the states based on where miles were actually driven.
The core concept: you pay fuel tax where you buy diesel, but you owe tax based on where you drive. If you drive more miles in high-tax states than where you buy fuel, you may owe additional tax. If you buy more fuel in high-tax states than your mileage there warrants, you may receive a credit.
How to use this estimator
- Total miles: All miles driven in IFTA jurisdictions during the quarter.
- Total gallons consumed: Total diesel used by your truck engine (not reefer).
- Tax-paid gallons: Gallons purchased at the pump where tax was collected by the station.
- Average tax rate: A blended estimate — the average state diesel fuel tax across your operating states.
Frequently Asked Questions
- Who is required to file IFTA returns?
- IFTA applies to qualified motor vehicles — generally commercial trucks with 3 or more axles or weighing over 26,000 lbs GVWR — that travel in two or more IFTA jurisdictions. If you operate only within one state, IFTA does not apply. Consult your base state for specific threshold rules.
- When are IFTA returns due?
- IFTA returns are filed quarterly with your base jurisdiction: January 31 (Q4), April 30 (Q1), July 31 (Q2), and October 31 (Q3). Late returns are subject to interest and penalties. If you owe tax, payment is due with the return.
- Does this calculator replace my official IFTA filing?
- No. This is a simplified estimator using a single average tax rate. Official IFTA calculations require per-jurisdiction mileage and the specific tax rate for each state or province. Use this tool for planning and budgeting — not for official tax reporting.
- What records do I need to keep for an IFTA audit?
- You need fuel purchase records showing gallons and the jurisdiction where each purchase was made (pump receipts or fuel card statements), plus mileage records by state or province for every trip. Most ELD systems can generate mileage-by-jurisdiction reports automatically. Keep records for at least 4 years — that's the standard IFTA audit retention requirement.
- What happens if I miss an IFTA filing deadline?
- Late returns typically carry a penalty of $50 or 10% of the net tax due, whichever is greater, plus interest on any unpaid tax. Filing on time — even if you can't pay in full — is better than not filing, since the late-filing and late-payment penalties are separate charges. Contact your base state IFTA office if you're unable to file on time; some jurisdictions allow payment plans.
Sources & Assumptions
- Average tax rate default ($0.42/gal) is a blended midpoint estimate. Official quarterly rates by jurisdiction are published by IFTA Inc. and updated each quarter.
- Official IFTA filing requires per-jurisdiction mileage and the specific rate for each state or province — this estimator uses a single blended rate and cannot substitute for that calculation.
- Reefer fuel is generally excluded from IFTA in most jurisdictions as it powers an auxiliary unit, not the propulsion engine — verify with your base state.
Disclaimer: This is a simplified IFTA estimator for budgeting purposes only. It uses a single average tax rate and does not perform the per-jurisdiction calculations required for official IFTA filing. Do not use this tool for your official IFTA return. Consult your base state IFTA authority for filing requirements.