Free tool · 4th quarter 2026 rates
IFTA calculator
Put in the miles you ran in each state and the gallons you bought there. You get the gallons you burned, the tax by state, and what you owe or get back.
Your quarter
One line per state. Add the gallons you bought in that state, if any.
- Total miles
- 1,000
- Total gallons
- 150
- Fleet MPG
- 6.67
Your return
You owe
$6.50
| STATE | BURNED | RATE | NET |
|---|---|---|---|
| CO | 45 gal | $0.335 | $15.08 |
| NM | 42 gal | $0.210 | $8.82 |
| TX | 63 gal | $0.200 | −$17.40 |
Burned gallons are miles divided by your fleet MPG, rounded to the nearest gallon. Net is burned minus bought, times the rate. A minus is a credit.
How the IFTA math works
- Add up every mile and every gallon for the quarter. Miles divided by gallons is your fleet MPG, rounded to two decimals.
- For each state, miles divided by fleet MPG is the gallons you burned there, rounded to the nearest gallon.
- Burned gallons minus the gallons you bought there, times the state's rate, is the tax due or the credit.
- Kentucky and Virginia add a surcharge on every gallon burned. It is never credited.
Add the states up and that's your return. This tool gives you the numbers. You still file with your base state.
Want the receipts behind the math? Read how we test it, or see the full fuel tax rate table.