How is this calculated?
Taxable gallons per jurisdiction = jurisdiction miles / fleet MPG Tax owed per jurisdiction = taxable gallons * tax rate - purchased gallons * tax rate Net IFTA = sum of jurisdiction tax owed Positive net = tax due; negative net = credit
Example: 800 miles in Texas at 6.5 MPG creates 123.08 taxable gallons. At $0.20 per gallon, tax is $24.62 before subtracting tax-paid Texas fuel purchases.
How do I use this calculator?
- Choose the unit or currency setting that matches your vehicle data.
- Enter the required vehicle, route, fuel, weight or loan values in the calculator form.
- Review inline warnings and correct any missing or negative inputs.
- Read the live result card for the primary answer and supporting totals.
- Use the worked example if you want to check the formula with sample values.
- Copy, share or print the results for comparison or record keeping.
What do the terms mean?
- IFTA
- International Fuel Tax Agreement for interstate motor fuel tax reporting.
- Jurisdiction
- An IFTA member state or province.
- Fleet MPG
- Total qualified miles divided by total gallons for the reporting period.
- Taxable gallons
- Jurisdiction miles divided by fleet MPG.
- Credit
- A negative net amount when fuel tax paid exceeds fuel tax owed.
What are real-world examples?
| Scenario | Inputs | Result | Notes |
|---|---|---|---|
| Texas lane | 800 mi, 6.5 MPG | $24.62 gross | $0.20 diesel rate |
| California lane | 500 mi, 6.5 MPG | $74.69 gross | $0.971 diesel rate |
| Ontario lane | 600 mi, 6.5 MPG | $22.98 gross | $0.249 diesel rate |
| Oregon miles | Report miles | $0 fuel rate here | Weight-mile tax separate |
What tips improve accuracy?
- Always verify current IFTA rates at IFTA Inc. before filing an official return.
- Use total fleet MPG for the quarter, not state-by-state MPG.
- Keep fuel receipts with jurisdiction, gallons and tax-paid status.
- Oregon has a zero IFTA fuel tax rate in the matrix but separate weight-mile rules.
- Some jurisdictions have surcharge lines that may not create credits.
- IFTA returns are generally due by the last day of the month after quarter end.
Did you know? EPA estimates commonly use 8.89 kg CO2 per gallon of gasoline and 10.18 kg CO2 per gallon of diesel for tailpipe carbon dioxide calculations.
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Frequently asked questions
IFTA Fuel Tax
IFTA fuel tax is a reporting system for qualified commercial motor vehicles that travel in more than one IFTA jurisdiction. Instead of buying separate fuel permits for each state or province, the carrier files one quarterly report through its base jurisdiction. The report compares miles driven and fuel purchased in each jurisdiction. The result can be tax due or a refund. Good mileage records, fuel receipts, and vehicle details are essential.
What is ifta tax
IFTA stands for International Fuel Tax Agreement. It is not a separate fuel tax added at the pump for everyone; it is a way for qualified motor carriers to report and share fuel taxes across states and Canadian provinces. If a truck buys fuel in one state but drives many miles in another, IFTA helps allocate tax fairly. Carriers usually file quarterly returns showing miles, gallons, MPG, and tax-paid fuel.
How to calculate ifta fuel tax
To calculate IFTA, first find total miles and total gallons for the fleet, then divide miles by gallons to get fleet MPG. Next, for each jurisdiction, divide miles driven there by fleet MPG to get taxable gallons. Subtract tax-paid gallons bought in that jurisdiction. Multiply the difference by that jurisdiction's tax rate. Positive amounts are tax due; negative amounts may be credits. Add all jurisdictions for the return total.
Do i need ifta under 26000
If the power unit has only two axles and its gross or registered weight is 26,000 lb or less, and the combination is not over 26,000 lb, it generally does not need IFTA. However, a vehicle with three or more axles may qualify regardless of weight, and a combination over 26,000 lb may qualify. Recreational vehicles are usually excluded. Always confirm with the base jurisdiction before interstate commercial travel.
Best ifta fuel tax calculator
The best IFTA calculator is one that matches the official quarterly tax rates, separates miles by jurisdiction, imports or records fuel receipts, calculates fleet MPG, and keeps audit-ready reports. For a small fleet, a clean spreadsheet may work if entries are accurate. For larger fleets, GPS or ELD-connected software saves time. The important point is not the brand; it is accurate miles, gallons, dates, jurisdictions, and rate updates.
Ifta diesel tax rates by state
IFTA diesel tax rates vary by jurisdiction and can change each quarter. Do not use an old saved rate table for a current return. Use the official IFTA tax matrix or your base jurisdiction's current rate chart for the quarter being filed. Enter the diesel rate for each state or province where the qualified vehicle traveled. Keeping the quarter, fuel type, and jurisdiction correct is critical for avoiding underpayment or audit problems.