Official IFTA rate data has not yet been loaded. Enter the applicable official rate manually.
Miles and fuel by jurisdiction
Assumptions used
Important — read before relying on this result
This tool is a calculation aid for estimating quarterly IFTA figures. It is not an official tax filing service. Verify rates and filing requirements with the applicable jurisdiction and current IFTA information before you file.
How this calculator works
IFTA exists to settle a mismatch: you buy fuel where it is convenient, but you burn it where you drive. The agreement redistributes fuel tax between jurisdictions so each one is paid for the fuel actually consumed inside its borders, rather than the fuel that happened to be pumped there.
For each jurisdiction the calculator works out how many gallons you should have used there, subtracts the gallons you actually bought there, and multiplies the difference by that jurisdiction’s tax rate. Positive means you owe; negative means you are owed a credit.
Work out your fleet MPG for the quarter
Total miles across every jurisdiction, divided by total gallons purchased across every jurisdiction. This is a whole-quarter figure, not a single trip — getting it wrong shifts every line on the return.
Work out taxable gallons per jurisdiction
Miles driven in that jurisdiction divided by your fleet MPG. This is the fuel you are treated as having burned there, regardless of where you bought it.
Subtract the gallons you bought there
The difference is what the jurisdiction is short, or over, on tax already collected at the pump.
Multiply by that jurisdiction’s rate
Rates differ by jurisdiction and by fuel type, and they change every quarter. The result is your net tax or credit for that line.
fleet MPG = total miles ÷ total gallons purchased taxable gallons = miles in jurisdiction ÷ fleet MPG net tax = (taxable gallons − gallons bought there) × rate
Worked example
Your fleet ran 6.5 MPG for the quarter. In one jurisdiction you drove 1,300 miles and bought 120 gallons, and the diesel rate there is $0.20 per gallon.
| Step | Working | Result |
|---|---|---|
| Taxable gallons | 1,300 ÷ 6.5 | 200.0 gal |
| Gallons purchased there | — | 120.0 gal |
| Difference | 200.0 − 120.0 | 80.0 gal |
| Net tax | 80.0 × $0.20 | $16.00 owed |
Had you bought 250 gallons in that jurisdiction instead, the difference would be −50 gallons and the line would show a $10.00 credit rather than an amount owed.
Why this calculator asks you for the rate
IFTA rates change every quarter, across roughly 58 jurisdictions, for several fuel types. That is hundreds of figures, all of which go stale on a fixed schedule.
Publishing rates that cannot be verified would be worse than publishing none — a stale rate produces a wrong filing, and a wrong filing is the driver’s problem, not the website’s. So this tool ships without a rate table and asks you to enter the official figure. The arithmetic is identical either way.
Take rates from the official IFTA, Inc. matrix for the quarter you are filing. Do not use third-party tax sites — they lag, and a lagging rate is the most common source of an incorrect return. Once the official matrix is loaded into this site, the jurisdiction field becomes a dropdown and the rate fills itself in.
What is not included
Surcharges
Several jurisdictions levy a fuel-use surcharge on top of the base rate, calculated separately. It is not in this figure.
Interest and penalties
Late filings accrue both. This calculator estimates the tax itself, not what happens if it is filed late.
Jurisdiction adjustments
Some jurisdictions apply their own credits, exemptions or special rules that a general calculation cannot capture.
Non-taxable miles
Certain toll roads and off-highway miles are exempt in some jurisdictions. Those need removing before you use these figures.
The filing itself
This is a calculation aid. Filing happens through your base jurisdiction, on their system, on their schedule.
Fuel type differences
Diesel, gasoline, LNG, CNG and propane carry separate rates. Run each fuel type as its own set of figures.
Getting your quarterly figures right
Reconcile miles first
Your jurisdiction mileage should tie back to your ELD or trip records before you calculate anything. Miles are where most errors originate.
Keep every fuel receipt
Gallons purchased must be evidenced. A missing receipt usually means the gallons cannot be claimed.
Compute MPG across the whole quarter
A per-trip MPG will not reconcile, and the mismatch shows up as a discrepancy across every jurisdiction line.
File even at zero
A return is generally required for every quarter you hold a licence, including quarters with no travel.
The honest summary
IFTA is not complicated arithmetic — it is four steps and one formula. What makes it painful is record-keeping: accurate jurisdiction miles, complete fuel receipts, and current rates.
Get those three right and the calculation takes minutes. Get any one of them wrong and no calculator can save the return.
Frequently asked questions
How are taxable gallons calculated?
Miles driven in a jurisdiction divided by your fleet MPG for the quarter. That is the fuel you are treated as having burned there, regardless of where you actually bought it.
Why is my figure negative?
You bought more fuel in that jurisdiction than you used there, so the line is a credit rather than an amount owed. This is normal and common in jurisdictions with cheap fuel where you top up but do not drive far.
Where do I get the official rates?
From IFTA, Inc. — the official rate matrix, published each quarter. Do not take rates from third-party tax sites; they lag behind, and a lagging rate is the most common cause of an incorrect return.
Why does this calculator not include the rates?
Because rates change quarterly across roughly 58 jurisdictions and several fuel types. Publishing figures that cannot be verified would produce wrong filings, and a wrong filing is your problem rather than ours. Entering the official rate yourself gives the identical result.
What MPG should I use?
Total miles for the quarter divided by total gallons purchased for the quarter, across the whole fleet or vehicle you are reporting. A per-trip MPG will not reconcile and the mismatch appears on every jurisdiction line.
Does this file my IFTA return?
No. It works out the figures. Filing happens through your base jurisdiction on their system and their schedule. This is a calculation aid, not a filing service.
Are surcharges included?
No. Several jurisdictions levy a fuel-use surcharge on top of the base rate, calculated separately. Interest, penalties and jurisdiction-specific adjustments are also outside this calculation.
Do I need to file if I did not travel?
Generally yes — a return is usually required for every quarter you hold an IFTA licence, including quarters with no travel. Check with your base jurisdiction.
Should each fuel type be calculated separately?
Yes. Diesel, gasoline, LNG, CNG and propane carry separate rates. Run each fuel type as its own set of figures.
What records do I need to keep?
Jurisdiction mileage that ties back to your ELD or trip records, and fuel receipts evidencing every gallon claimed. Missing receipts usually mean the gallons cannot be claimed at all.
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