Important: This is a simplified estimator using a single average tax rate. It does not replace official IFTA reporting. Official IFTA calculations require per-jurisdiction mileage and the specific tax rate for each state or province.

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.

Total diesel consumed by your truck engine (not reefer)
Gallons purchased at retail pump (tax already paid)
Blended average across all states traveled. Typical range: $0.30–$0.55/gal.
Enter your quarterly totals and click Calculate.

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

  1. Total miles: All miles driven in IFTA jurisdictions during the quarter.
  2. Total gallons consumed: Total diesel used by your truck engine (not reefer).
  3. Tax-paid gallons: Gallons purchased at the pump where tax was collected by the station.
  4. Average tax rate: A blended estimate — the average state diesel fuel tax across your operating states.
For accurate IFTA filing, you need per-state mileage records and the current tax rate for each state you operated in. This estimator uses a single blended rate as a planning approximation only. Contact your base state IFTA office for official filing guidance.

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.

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.