IFTA Fuel Tax Calculator
Enter miles driven and gallons purchased in each jurisdiction. We compute net tax owed (or refund) per state using Q3 2026 rates.
| State | Miles | Gallons bought | Rate | Net (owed / refund) | |
|---|---|---|---|---|---|
| $0.200 | +$0.00 | ||||
| $0.200 | +$0.00 | ||||
| $0.285 | +$0.00 |
How IFTA works
IFTA (International Fuel Tax Agreement) reconciles fuel taxes across the 48 contiguous US states and 10 Canadian provinces. You pay diesel tax at the pump. At quarter-end, your base state collects whatever you owe to other jurisdictions or refunds whatever you overpaid.
The math: (miles in state ÷ fleet MPG) × state tax rate = tax owed. Subtract gallons actually purchased in that state × state rate. Positive = owe. Negative = refund.
Rates change quarterly. We use Q3 2026 rates from IFTA Inc.. See the full IFTA filing guide for due dates and what to file with your base state.
Note: Oregon uses a weight-mile tax instead of fuel tax — IFTA rate shows $0.00 but you owe Oregon's separate per-mile tax for any miles run there.