Montana Sales Tax Calculator (2026) — Add or Reverse Tax
Montana's combined sales tax rate is 0.00% (0.00% state). Use the calculator below to add Montana sales tax to a price, or reverse a tax-included total to find the pre-tax price and exact tax amount.
How to use this calculator:
- Adding tax — enter a pre-tax price, pick "Add tax to price," and the calculator applies the Montana rate to show the tax amount and final total.
- Reversing (extracting) tax — enter a total that already includes tax, pick "Extract tax from total," and the calculator divides by 1 + the rate to isolate the pre-tax price and the exact tax paid.
- Pick the rate that matches your situation: the average combined rate is a good statewide estimate, but the state-only or maximum-local rate is more precise if you know the exact city or county.
Understanding Montana Sales Tax
Montana's state sales tax rate is 0.00%, with no additional local sales tax in most of the state.
Montana charges no general state or local sales tax, though it does levy targeted taxes on lodging and rental cars aimed at tourists.
Montana also levies a state income tax, which shapes how much the state relies on sales tax revenue relative to other funding sources.
Groceries
Exempt from Montana state sales tax.
Largest city
Billings
State income tax
Yes
Why Reverse Sales Tax Calculation Matters
Receipts, invoices, and marketplace payouts usually show only the tax-included total — not the pre-tax price. Reversing the calculation matters for bookkeeping (separating revenue from tax collected), expense reports (reimbursing only the pre-tax cost), and price comparisons (checking what an item actually costs before Montana's tax is applied). Because dividing by (1 + rate) is not the same as simply subtracting the rate from the total, doing this by hand is a common source of errors — the calculator above handles it exactly.
History & Rate Breakdown
Montana has never enacted a general statewide sales tax, and Article VIII, Section 16 of the state constitution caps any future general sales or use tax at 4% — a high bar that has kept the idea largely off the table in state politics for decades.
There is no general sales tax rate to break down anywhere in Montana. The one exception is the local option 'resort tax,' capped at 3% (plus an optional 1% infrastructure tax, for up to 4% total), which only small, high-tourism communities under a population cap — Big Sky, Red Lodge, and West Yellowstone among them — may adopt with local voter approval.
Where the Money Goes
Montana's resort tax exists specifically to let small, high-tourist-traffic communities recover infrastructure costs from visitors rather than overburdening local residents through property tax — a targeted, opt-in alternative to a general sales tax the state constitution otherwise discourages.
Business Use Case: Registering & Collecting Montana Sales Tax
A hotel or restaurant operating in Big Sky or West Yellowstone must collect the local resort tax on top of its normal pricing, while the identical business just outside those town boundaries — or anywhere else in Montana — charges no sales tax at all.
Sales Tax Terms Glossary
Combined rate
The state sales tax rate plus any applicable local (city, county, or special district) rates — the actual rate charged at checkout in a given location.
Reverse sales tax
The process of working backward from a tax-included total to find the pre-tax price and the exact tax amount, using total ÷ (1 + rate) = pre-tax price.
Economic nexus
A sales threshold (in dollars, transaction count, or both) that obligates an out-of-state seller to collect and remit sales tax even without a physical presence in the state.
Marketplace facilitator
A platform (e.g. Amazon, Etsy, eBay) that collects and remits sales tax on behalf of third-party sellers under most states’ marketplace facilitator laws.
Real-World Example
A $500.00 purchase in Montana at the average combined rate of 0.00%:
- Tax amount: $500.00 × 0.00% = $0.00
- Total price: $500.00 + $0.00 = $500.00
Montana Sales Tax Compliance for Sellers
Montana has no general state sales tax, so there is no economic nexus threshold to track for state-level sales tax purposes. Sellers should still confirm whether any local jurisdiction-level tax applies.
Frequently Asked Questions — Montana Sales Tax
What is the sales tax rate in Montana?▾
Does Montana tax groceries?▾
Does Montana have a state income tax?▾
When do online sellers need to collect Montana sales tax?▾
How do I calculate Montana sales tax on a purchase?▾
How do I reverse Montana sales tax to find the price before tax?▾
What is the formula to back out sales tax from a receipt in Montana?▾
References & Sources
Rates last verified January 2026. Montana sales tax rates and thresholds can change — always confirm current figures with the Montana Department of Revenue before filing or invoicing. This tool is for estimation and educational purposes only and is not tax, legal, or accounting advice.
Jordan Hayes
Verified AuthorLead Content Editor & Personal Finance Specialist
Jordan Hayes is a personal finance content strategist with 9+ years building educational finance and health resources. He has written and fact-checked over 200 personal finance guides covering mortgage amortization, retirement planning, tax strategy, and budgeting. His work applies IRS publications, Federal Reserve data, and peer-reviewed research to make complex calculations accessible.