Q4 2026 IFTA diesel rate

Montana IFTA fuel tax rate, Q4 2026

MTMontana · diesel$0.2975/gal

Unchanged from Q3 2026.

Checked 2026-10-14 against mdt.mt.gov, Montana's own published rate.

Calculate Montana for Q4 2026Free. No account.

What you owe Montana

IFTA apportions your fuel by miles. Divide total miles by total gallons for fleet MPG, turn your Montana miles into taxable gallons, subtract the tax-paid gallons you bought in Montana, and multiply by $0.2975.

Example: 1,000 miles in Montana at 6.5 MPG is 153.85 taxable gallons. With 100 tax-paid gallons bought there, 53.85 × $0.2975 = $16.02 owed to Montana.

This rate is for diesel, Q4 2026. You still file with your base jurisdiction; keep your trip records and receipts.